Traffic Sign Recognition, Basic Function - GF54.30-D-9901A
Model All (Light transporter)
With Code JA9 (Traffic Sign Assist)
Overview
This document contains information on:
- General
- Function requirements
- Function
General
Speed sign or traffic sign recognition evaluates the information on traffic signs and interprets its meaning. This enables identification of the maximum permissible speed and passing restrictions for the current route. It also enables identification of crosswalks or access restrictions. This information is then displayed to the driver. Supplementary restriction signs, such as speed limits in wet conditions, are also taken into account.
The driving speed is compared with the maximum permissible speed. The detected maximum permissible speed can be adopted as the new specified speed.
If set accordingly by the driver, a warning indicates when the maximum permissible speed has been exceeded. No-entry signs are also recognized and the driver is prompted to check their direction of travel, if necessary. The driver can also be warned about people in the vicinity of crosswalks.
On vehicles with Traffic Sign Assist, the traffic sign recognition system additionally evaluates information from the digital road map of the navigation system.
Depending on the vehicle, the system also supports the driver during forward and intersection situations as well as in unclear and changing situations (variable maximum permissible speeds, e.g. on sign gantries or at construction sites). "Additional warning contents" can be activated on a country-specific basis. These include a warning of pedestrians located in the sensor-detected danger zone at pedestrian crossings. The system can also warn the driver against driving the wrong way into roads or onto roundabouts, and provide a two-stage warning before unintentionally driving past stop signs and "Yield" traffic signs.
Traffic sign recognition can reduce the risk of traffic offenses or accidents. Traffic sign recognition is operated via the multimedia system.
Function requirements
The following conditions must be met so that traffic sign recognition can be activated:
- Circuit 15 R ON
- Vehicle moving forward
Function
The multifunction camera behind the windshield detects traffic signs, e.g. at the edge of the road, on sign gantries or at construction sites. The integrated picture recognition module evaluates the picture data from the multifunction camera. The navigation system (depending on the equipment) provides information from the digital road map.
When determining the maximum permissible speed, the traffic sign recognition system also takes into account the following information:
- Actions of the windshield wiper system that indicate rain and a wet roadway.
- Outside temperature, from which the danger of slippery conditions can be derived.
- Trailer operation (vehicles with trailer hitch); other specifications apply for journeys with trailers.
In addition, the traffic sign recognition system evaluates the following function-relevant parameters:
- Engine operating status
- Direction of travel
- Vehicle speed
- Vehicle longitudinal and lateral acceleration as well as yaw rate
- Distance and angle to other road users and objects
- Steering angle
The traffic sign recognition system is continuously active in the background. In other words, the traffic signs are continuously detected by the multifunction camera and evaluated by the integrated picture recognition module.
The multifunction camera evaluates both circular and square contours. Speed limits, prohibitory and derestriction signs including restrictions are detected both in countries with signage in accordance with the Vienna Convention as well as in the USA and Canada.
Non-relevant signs (supplementary signs that, for example, are relevant for a turnoff lane) are ignored.
If route guidance is active (depending on the equipment), supplementary signs will be shown immediately if they are relevant for the active route guidance.
Inadvertent "wrong-way" driving can be prevented by the visual and acoustic wrong-way warning function of the traffic sign recognition system. This is because the system also detects no-entry signs at slip roads of expressways, freeways and roundabouts, and compares them with the information from the navigation system.
The pictures recorded by the multifunction camera are compared with stored data records by the picture recognition module. The detected traffic signs are matched to the respective valid road traffic regulations.
Depending on the vehicle, the system also detects right-of-way signs (stop signs or yield signs) and warns the driver either solely visually or visually and acoustically using a two-stage warning up to a speed of approx. 70 km/h.
Warnings about pedestrians on pedestrian crossings and warnings about unintentionally driving past stop signs can be activated or deactivated by the driver (permanently) in the Driving Assistance menu of Traffic Sign Assist. The type of warning and the warning threshold can also be adjusted. However, country-specific warnings about driving against the prescribed direction of travel are permanently active.
| Additional basic functions | |||
| Front multifunction camera, basic function | GF54.71-D-9890A |