Construction zone sign detection using light detection and ranging

A non-transitory computer readable medium having stored thereon instructions executable by a computing device of a vehicle to cause the computing device to perform functions comprising:

• receiving, from a light detection and ranging (LIDAR) sensor coupled to the computing device, LIDAR-based information comprising (i) a three-dimensional (3D) point cloud of a vicinity of a road on which the vehicle is travelling, wherein the 3D point cloud comprises points corresponding to light emitted from the LIDAR and reflected from one or more objects in the vicinity of the road, and (ii) intensity values of the reflected light for the points;
• selecting a portion of the 3D point cloud representing an area at a height greater than a predetermined threshold height from a surface of the road;
• identifying a shape in the selected portion;
• determining a likelihood that the identified shape represents a construction zone sign based on an outline of the shape and respective intensity values of points representing the shape in selected portion;
• in response to the likelihood exceeding a threshold likelihood, determining a type of the construction zone sign based on the identified shape and determining a severity of road changes based on the type of the construction zone sign;
• modifying a control strategy associated with a driving behavior of the vehicle based on the likelihood and the severity of the road changes;
• and
• controlling the vehicle based on the modified control strategy.

A control system for a vehicle, comprising:

• a light detection and ranging (LIDAR) sensor configured to provide LIDAR-based information comprising (i) a three-dimensional (3D) point cloud of a vicinity of a road on which the vehicle is travelling, wherein the 3D point cloud comprises points corresponding to light emitted from the LIDAR and reflected from one or more objects in the vicinity of the road, and
• (ii) intensity values of the reflected light for the points;
• and
• a computing device in communication with the LIDAR sensor and configured to:
• receive the LIDAR-based information;
• select a portion in of the 3D point cloud representing an area at a height greater than a predetermined threshold height from a surface of the road;
• identify a shape in the selected portion;
• determine a likelihood that the identified shape represents a construction zone sign based on an outline of the shape and respective intensity values of points;
• in response to the likelihood exceeding a threshold likelihood, determine a type of the construction zone sign based on the identified shape and determine a severity of road changes based on the type of the construction zone sign;
• modify a control strategy associated with a driving behavior of the vehicle based on the likelihood and the severity of the road changes;
• and
• control the vehicle based on the modified control strategy.