Method for increasing safety at a crossing system

A device configured to increase safety at a crossing system including a crosswalk, the device comprising a computer configured to:

• receive environmental signals representing an environment of a motor vehicle approaching the crossing system;
• based on the environmental signals, specify an initial set of one or more boundary conditions and/or one or more instructions for action that define constraints that must be satisfied by a target trajectory for a crossing system maneuver of the motor vehicle;
• plan, by execution of planning software and based on the environmental signals, the crossing system maneuver for the motor vehicle by attempting to compute the target trajectory to satisfy the initial set of boundary conditions and/or instructions for action;
• determine, during the planning, that no target trajectory exists that satisfies the initial set of boundary conditions and/or instructions for action;
• in response to determination that no target trajectory exists, modify the initial set of boundary conditions and/or instructions for action to form a relaxed set of boundary conditions and/or instructions for action;
• re-plan, by the execution of the planning software, the crossing system maneuver using the relaxed set of boundary conditions and/or instructions for action;
• iteratively repeat the modifying and re-planning until the computer executing the planning software computes a fallback target trajectory that satisfies a current iteration of the boundary conditions and/or instructions for action, each iteration, after a first of the iterations, further relaxing the boundary conditions compared to the immediately preceding iteration;
• and
• control operation of the motor vehicle in accordance with the computed fallback target trajectory to perform the crossing system maneuver.

A non-transitory machine-readable storage medium on which is stored a computer program for increasing safety at a crossing system including a crosswalk, the computer program, when executed by a computer, causing the computer to perform the following steps:

• receiving environmental signals representing an environment of a motor vehicle approaching the crossing system;
• based on the environmental signals, specifying an initial set of one or more boundary conditions and/or one or more instructions for action that define constraints that must be satisfied by a target trajectory for a crossing system maneuver of the motor vehicle;
• planning, by execution of planning software and based on the environmental signals, the crossing system maneuver for the motor vehicle by attempting to compute the target trajectory to satisfy the initial set of boundary conditions and/or instructions for action;
• determining, during the planning, that no target trajectory exists that satisfies the initial set of boundary conditions and/or instructions for action;
• in response to determining that no target trajectory exists, modifying the initial set of boundary conditions and/or instructions for action to form a relaxed set of boundary conditions and/or instructions for action;
• re-planning, by the execution of the planning software, the crossing system maneuver using the relaxed set of boundary conditions and/or instructions for action;
• iteratively repeating the modifying and re-planning until the computer executing the planning software computes a fallback target trajectory that satisfies a current iteration of the boundary conditions and/or instructions for action, each iteration, after a first of the iterations, further relaxing the boundary conditions compared to the immediately preceding iteration;
• and
• controlling operation of the motor vehicle in accordance with the computed fallback target trajectory to perform the crossing system maneuver.