Abstract: This application provides a method and an apparatus for generating road network data of an intersection area, and the intersection area connects a plurality of roads. The method includes: obtaining data of a road link of each of the plurality of roads, where the road link includes an entry link and an exit link; calculating coordinates of an intersection point of an extension line of the entry link of each road and an extension line of an exit link of a neighboring road based on the data of the road link of each of the plurality of roads, where the coordinates of the intersection point are coordinates of an intersection node; and the neighboring road is a road counterclockwise adjacent to the road; or the neighboring road is a road clockwise adjacent to the road, where two intersection nodes in sequence are endpoints of an intra-intersection link.

Abstract: A map data construction method and device, where the method includes obtaining first basic safety information packets of a vehicle, where the first basic safety information packets include an information packet of the vehicle that is collected when a safety event occurs, obtaining first basic safety information data from the first basic safety information packets, where the first basic safety information data includes parameter information of the vehicle and extended safety information, the parameter information of the vehicle indicates a driving state and an appearance information of the vehicle, and the extended safety information is used to indicate a safety state of the vehicle and a safety state of a road, and performing model processing based on the first basic safety information data to generate the map data.

Abstract: The present application relates to an easy-to-install LED double-ring ceiling lamp, including a base plate, a LED light source board, a driving power supply, a translucent cover and a press ring. The LED light source board and the driving power supply are installed on the base plate, the translucent cover is covered on the base plate, and the press ring is covered outside the translucent cover and configured to support the translucent cover. The press ring and the base plate are detachably connected by multiple installation column-shaped bolts, and at least one of the multiple installation column-shaped bolts is a bendable installation column-shaped bolt.

Abstract: The present application relates to an easy-to-install LED double-ring ceiling lamp, including a base plate, a LED light source board, a driving power supply, a translucent cover and a press ring. The LED light source board and the driving power supply are installed on the base plate, the translucent cover is covered on the base plate, and the press ring is covered outside the translucent cover and configured to support the translucent cover. The press ring and the base plate are detachably connected by multiple installation column-shaped bolts, and at least one of the multiple installation column-shaped bolts is a bendable installation column-shaped bolt.