Method and system for calculating and displaying travel range information

A vehicle comprising:

• an energy storage system;
• a motor/generator unit which is electrically connected to the energy storage system and adapted for generating torque for propelling the vehicle in an electric-only (EV) mode;
• a display screen;
• and
• host machine in communication with a geospatial mapping database, wherein the geospatial mapping database provides a map of road segments, the host machine being operable for:
• determining the current position of the vehicle;
• calculating a maximum theoretical range for the EV mode with respect to the current position of the vehicle;
• formulating a value function via a dynamic programming equation which calculates the minimum cost to travel from each of a set of sampled points on the map to the current position of the vehicle within one of the maximum theoretical range and a displayable subset of the maximum theoretical range;
• calculating a solution to the value function for each point in the set of sampled points using a cost which is a function of the attributes of each road segment appearing on the map;
• forming a feasible range set as a closed curve from the mathematical hull of all points in the maximum theoretical range having a value function solution less than a corresponding limit;
• and
• displaying the feasible range set as at least a perimeter of the closed curve via the display screen to thereby indicate the effective EV range of the vehicle with respect to the current position of the vehicle.

A method of operating a display system for a vehicle, the display system having a display screen and a host machine which is in communication with a geospatial mapping database that provides a map of road segments, the method comprising:

• determining the current position of the vehicle;
• formulating a value function via a dynamic programming equation which calculates the minimum cost to travel from each of a set of sampled points on the map to the current position of the vehicle within one of the maximum theoretical range and a displayable subset of the maximum theoretical range;
• calculating a solution to the value function for each point in the set of sampled points using a cost which is a function of the attributes of each road segment appearing on the map;
• forming a feasible range set as a closed curve from the mathematical hull of all points in the maximum theoretical range having a value function solution less than a corresponding limit;
• and
• displaying the feasible range set as at least a perimeter of the closed curve via the display screen to thereby indicate the effective EV range of the vehicle with respect to the current position of the vehicle.