Technical Description

The front camera recognizes differently shaped signs and the symbols. The information is sent to the central driver assistance control unit by the evaluation of the images. Since the traffic signs of different countries look different, these must be entered for the region concerned.

Traffic Sign Recognition (TSR) is a driver assistance system that shows drivers the current speed limit and any other traffic signs on the road from which is possible to infer the speed limit. Traffic sign recognition uses a camera mounted on the front windshield to capture traffic signs on the road ahead. The system uses recognition software to detect a traffic sign and then display this information on the infotainment and/or head-up displays. Speed limits are also inferred from ISA maps. When Adaptive Cruise Control is active and the Intelligent Speed Assist button is pressed, the vehicle's speed will be automatically adjusted in accordance with the speed limit detected and the user-configured speed offset value that has been set. It will issue a warning if the driver exceeds these speed limits.

In addition, the system can also detect other non-speed-related traffic signs including bicycle paths, expressways, tunnels, slippery roads, pedestrian crossings. In the US, it will recognize speed limit, ramp speed, curve speed, school speed, end of speed limit, etc.

Activation: The system is activated when the vehicle's speed is over x km/h.

Deactivation: The system is deactivated when vehicle's speed is less than x km/h, or the user switches it OFF at the HMI.

According to the speed limit and vehicle's speed, the function will trigger the appropriate warning level. There will be 3 warning levels. These can be:

• No warning: vehicle speed < speed limit (TBD)
• Level 1 warning: (vehicle speed - speed limit)/speed limit < 5% -> the speed sign flashes on the IPC with frequency of 1Hz (tbd)
• Level 2 warning: 5 % <= (vehicle speed - speed limit)/speed limit < 10% -> the speed sign flashes on the IPC with a frequency of 2Hz (tbd)
• Level 3 warning: 10 % <= (vehicle speed - speed limit)/speed limit -> the speed sign flashes on the IPC with frequency of 4Hz (tbd)

If there is no speed limit or end of speed limit, the warning function does not work.

The function sends the recognition sign and warning signals to the infotainment system, which informs the driver.

The driver can enable/disenable the function on the MHU.

If the function detects any failure of itself or ADAS systems, it will trigger a MALFUNCTION warning and send it to the infotainment system, to alert the driver. The ADAS system can detect hardware/software failures that stop the function from working properly; the not available function alert is sent to the HMI/IPC, etc.

TSM system performance may be impacted in the following conditions:

• Poor visibility due to snow, fog or heavy rain
• Due to glare from oncoming traffic or the sun
• At high speed
• If the camera's visual field is covered with dirt or stickers
• If the traffic signs are completely or partially covered
• If traffic signs do not conform to the standard format
• If traffic signs are damaged or bent
• If traffic signs are displayed on sign holders with electronic signs
• If the traffic signs or the roadways have changed and the
• Navigation data is no longer up-to-date