Operation principle of road sign information
The road sign information uses a video camera with algorithms to detect and classify round, triangular and rectangular road signs, including the start and ends of stretches where speed limits are in force, or where passing is prohibited. It also recognizes “no entry”, “stop”, “right of way” and “road works” signs. The road sign information also classifies relevant supplementary signs, such as time limits, signs applicable only to specific vehicle types and turn arrows.
When the assistant identifies a road sign, it shows this information using icons in the dashboard display. The system reliably detects road signs, whether they are sited on actual signs, variable message systems or gantries.
In addition, a range of warning functions can be realized, including warning the driver before the speed limit is exceeded, warning against passing on a stretch where such maneuvers are prohibited, or letting the driver know when a “stop” sign or “no entry” sign has been overlooked.
In combination with a navigation system, the assistant can use information that a camera typically cannot detected, for example, to distinguish between urban and rural roadways or interpret text-based supplementary signs, such as the validity period of speed limits.