Motion planner for unmanned ground vehicles traversing at high speeds in partially known environments

A method for planning a path for an unmanned ground vehicle, comprising:

• determining a path, via a global path planner, to be traversed by the unmanned ground vehicle to reach a goal location, the determined path comprises a polygonal path, the polygonal path includes at least one discontinuity wherein the unmanned ground vehicle is required to change heading so that the polygonal path includes a first path substantially straight segment and a second substantially straight path segment, the second substantially straight path segment joining the first substantially straight path segment at the at least one discontinuity;
• and
• generating a motion profile by revising the determined path to account for at least one constraint on maneuverability of the unmanned ground vehicle, the motion profile allowing traversal of a revised path by the unmanned ground vehicle to reach the goal location, the revised path comprises a smoothed path with at least one arc that complies with the at least one constraint on the maneuverability of the unmanned ground vehicle, the revised path based upon a curve speed of the unmanned ground vehicle following said at least one arc of the smoothed path and a turning rate of the unmanned ground vehicle;
• wherein the unmanned ground vehicle is suitable to traverse the revised path at a speed greater than the speed at which the unmanned ground vehicle is suitable to traverse the determined path, the curve speed of the unmanned ground vehicle being a highest speed following said at least one arc to avoid a rollover of the unmanned ground vehicle, the motion profile further including a speed profile whereby the unmanned ground vehicle decelerates to said curve speed while avoiding a rollover of the unmanned ground vehicle when beginning said at least one arc of the smoothed path and maintains said curve highest speed through said at least one arc.

An unmanned ground vehicle, comprising:

• a global path planner configured to determine a path to be traversed by the unmanned ground vehicle to reach a goal location, the path determined by the global path planner comprises a polygonal path, the polygonal path including at least one discontinuity where the ground vehicle is required to change heading so that the polygonal path includes a first substantially straight path segment and a second substantially straight path segment, the second substantially straight path segment joining the first substantially straight path segment at the discontinuity;
• and
• a local motion planner in communication with the global path planner configured to revise the path determined by the global path planner to generate a motion profile accounting for at least one constraint on maneuverability of the unmanned ground vehicle, the motion profile providing a revised path for being traversed by the unmanned ground vehicle to reach the goal location, the revised path comprises a smoothed path with at least one arc that complies with the at least one constraint on the maneuverability of the unmanned ground vehicle, the local motion planner creating the revised path based upon a curve speed of the unmanned ground vehicle following act the at least one arc of the smoothed path and a turning rate of the unmanned ground vehicle;
• said unmanned ground vehicle is configured to traverse the revised path at a speed greater than the speed at which the unmanned ground vehicle is configured to traverse the path determined by the global path planner, the curve speed of the unmanned ground vehicle being a highest speed following said at least one arc to avoid a rollover of the unmanned ground vehicle, the motion profile further including a speed profile whereby the unmanned ground vehicle decelerates to said curve speed while avoiding a rollover of the unmanned ground vehicle when beginning said at least one arc of the smoothed path and maintains said curve speed through said at least one arc.