Traffic Sign Recognition

Courtesy of CHRYSLER GROUP, LLC

Components of the Traffic Sign Recognition (TSR) system:

• Body Control Module (BCM) (1)
• Display Screen Module (DSM) (2)
• Forward Facing Camera/HALF (FFC/HALF) Module (3)
• Instrument Panel Cluster (IPC)

The TSR system uses camera traffic sign information and map data information to determine the unconditioned speed limit for the current driving scenario and displaying this speed limit information to the customer. In certain use-case scenarios, the TSR system provides supplementary information relative to conditioned speed limits (e.g., speed limit under specific weather conditions, time, etc.). In addition, the TSR system will provide indications to the customer regarding the presence of overtaking ban (i.e., no passing) signs.

The TSR system provides a visual warning indication when the customers vehicle speed exceeds the unconditioned speed limit. The customer is capable of enabling and disabling the TSR system through the customer settings menu in the DSM.

The TSR system performs the following:

• Correctly operate in any country or region specified by the product grid.
• Provide the correct sign information in the case of either a fixed or variable speed limit.
• Provide the correct information in the case of either a permanent or temporary speed limit.
• If there is lane-specific speed limits, the system will only provide the traffic sign information relative to the lane in which the host vehicle is traveling.

The TSR system will ignore the following:

• Lane-specific speed limits that do not apply to the lane in which the host vehicle is traveling.
• Radar speed displays which reflect the current speed of the host vehicle or other vehicles.
• Advisory (i.e. recommended) speed signs.
• Minimum speed limit signs.
• Traffic signs not related to the path of the host vehicle (e.g. traffic sign posted on exit or parallel roads).
• Traffic signs embedded into a non-relevant traffic sign.

The FFC/HALF is used to perform the following functions in the TSR system:

• Detect the following primary traffic signs, defined as signs whose meaning and validity are exhaustively described by the sign itself:
  • Speed limits (i.e. both unconditioned and supplementary).
  • End of speed limit.
  • No passing zone.
  • End of no passing zone.
• Detect the following additional signs, defined as signs which indicate the validity of the primary signs they are linked with:
  • Restrictions for environmental conditions (e.g. snow, rain, fog, etc.).
  • Restriction for end of limit.
  • Restriction for time.
  • Validity at night only.
  • Other types (e.g., hazardous materials, arrows, exit, etc.).

The FFC/HALF will perform the following functions in the TSR system:

• Determine the validity of the traffic signs detected according to:
  • The detection of speed limit start/end signs.
  • The form of way
  • The time and/or the distance traveled relative to each traffic sign.
• Determine the most reliable information any time new information is detected and the map data:
  • The unconditioned speed limit.
  • The presence of a supplementary speed limit with its restriction type.
  • The presence of no passing zones.
• Provide all the necessary information for visualization to the IPC.

The TSR system operates when the ignition is in the RUN or START position assuming that the vehicle PROXI identifies that the TSR system is equipped.

The FFC/HALF combines the camera input with the map data inputs to perform the camera/map data fusion and arbitration process. The map data continuously monitors the vehicle position and provides the information related to its path as long as the GPS signal and the map data are available. If there is a contradiction between the camera and map data inputs, the FFC/HALF performs an arbitration and priority logic process to determine the best course of action.