ROAD SIGN ASSIST SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The main components in the RSA have the following functions.

      Item Function
      Pre-crash Safety City Sensor Monocular Camera Sensor Captures road signs
      Pre-crash Safety City Sensor ECU Performs RSA system control based on information of road signs captured by the monocular camera sensor.
      Combination Meter Assembly Multi-information Display

      • Displays road signs recognized by the pre-crash safety city sensor.

      • The RSA system can be turned on and off through the settings tab.
      Buzzer Sounds for speed limit exceeded and no overtaking notifications.
      ECM Sends a shift position signal to the pre-crash safety city sensor.
      Brake Actuator Assembly Skid Control ECU Sends a vehicle speed signal from the speed sensor to the pre-crash safety city sensor.
      Main Body ECU (Multiplex Network Body ECU) Sends country specification information signals to the pre-crash safety city sensor.
      Air Conditioning Amplifier Assembly Sends an ambient temperature signal to the pre-crash safety city sensor.
      Airbag Sensor Assembly Yawrate Sensor Detects the yaw rate and lateral/longitudinal deceleration of the vehicle and transmits the signal to the pre-crash safety city sensor.
      Spiral Cable with Sensor Sub-assembly Steering Sensor Detects the angle and direction of steering and transmits a signal to the pre-crash safety city sensor.
      Central Gateway ECU (Network Gateway ECU)* Gateway function of CAN communication.

      *: Models with central gateway ECU (network gateway ECU)

  2. FUNCTION


    1. The RSA system uses the pre-crash safety city sensor to recognize the road signs listed below. Furthermore, representative examples are given for each type of recognizable sign.

      Category Sign Type Example of Recognizable Sign
      Speed Limit Round maximum speed limit/End of speed limit A01T0X8
      No Overtaking No overtaking/End of no overtaking A01T13U
      Supplemental Signs Road condition signs Ramp Way A01T0RZ
      Rain A01T151
      Ice A01T0T7
      All Canceled (All restrictions canceled. Return to default road regulations.) A01T159

    2. The RSA system uses the pre-crash safety city sensor to recognize road signs and displays recognized information on the multi-information display. Items displayed on the multi-information display are categorized as shown below. Furthermore, representative examples are given for each category of items displayed on the multi-information display.

      Category Display Example Details
      Speed Limit Related A01T0ZX

      • Informs the driver of the maximum speed limit of the currently driven road.

      • The displayed sign reflects the speed limit on the recognized sign.
      No Overtaking Related A01T13S Informs the driver when they are in a no overtaking zone on the currently driven road.
      All Canceled (All restrictions canceled. Return to default road regulations.) A01T159 Informs the driver when all applicable prohibitions, such as speed limit and no overtaking, have ended.
      Speed Limit with Supplemental Sign Related Ramp Way A01T11N Informs the driver of the ramp way direction. However, this item is not displayed when making a lane change without operating the turn signal light.
      Rain A01T0S8 Informs the driver of the maximum speed limit on the currently driven road when it is raining or the road surface is wet.
      Ice A01T0OK Informs the driver of the maximum speed limit on the currently driven road when there is accumulated snow or ice.
      Blank A01T0W7 The display is blank when the system is unable to recognize a supplemental sign.

    3. Notification functions are used in the RSA system which invert the colors of displayed signs, flash signs, etc. to notify the driver.


      1. Speed Limit Exceeded Notification


        • While a speed limit sign is displayed, if the actual vehicle speed exceeds the speed limit plus a designated threshold*, the colors of the displayed sign are inverted. For example, if the threshold is set to 5 km/h and the speed limit sign is 60 km/h, the colors of the displayed sign are inverted when the actual vehicle speed exceeds 65 km/h. Furthermore, the system also inverts a speed limit sign with supplemental sign in the same way. However, the system does not invert the colors of the supplemental sign.

        • The buzzer may be set to sound during notifications through the customization function. However, if a speed limit recognized from a speed limit with supplemental sign is exceeded, the buzzer does not sound.

        • This notification is judged according to the speed units estimated by the monocular camera sensor. When moving to a region with different speed units, notifications may be incorrectly issued until learning is complete. (The user can change speed units of the meter for the given region, therefore displays and notifications can be correctly issued directly after moving to a region with different speed units.)

          Tech Tips

          *: The threshold can be adjusted to 1 of 3 levels through the customization function.

        Notification Method Display Example
        Inverted Display A01T0U1

      2. No Overtaking Notification


        • While a no overtaking sign is displayed, if the system detects that the vehicle is attempting to overtake another vehicle, the system flashes the displayed sign.

        • The buzzer may be set to sound during notifications through the customization function.

        Notification Method Display Example
        Flashing Display A01T0XT

  3. SYSTEM CONTROL


    1. The RSA can be turned on or off through the settings tab of the multi-information display.

    2. A customization function is used for the RSA, which allows settings such as the notification method and level for exceeding the speed limit to be changed. Setting changes are made through the customization tab of the multi-information display. Refer to the Repair Manual for details.

    3. RSA Control Pattern 1


      1. After a road sign is recognized by the pre-crash safety city sensor and the vehicle passes by, the sign is displayed on the multi-information display.

      2. While a sign is displayed on the multi-information display, if a new road sign is not recognized within a specified distance, display of the current sign is turned off.

        A01T10HE01
        *1 Road Sign Recognized
        *2 Specified Distance Driven
        *3 Sign Display Off
        *4 Sign Display On

    4. RSA Control Pattern 2


      1. When the engine switch is turned off while a sign is displayed on the multi-information display, the same sign is displayed when the ignition switch is turned ON again.

        A01T0SQE01
        *1 Engine Switch off (IG)
        *2 Engine Switch on (IG)
        *3 Sign Display On

    5. RSA Control Pattern 3


      1. While a sign is displayed on the multi-information display, the sign is turned off when turning left or right onto a new road.

        A01T17BE01
        *1 Road Sign Recognized
        *2 Sign Display Off
        *3 Sign Display On

  4. DIAGNOSIS


    1. If a malfunction is detected in the RSA system the pre-crash safety city sensor. cancels the RSA, sounds the buzzer in the combination meter assembly, and displays a message on the multi-information display to inform the driver of the malfunction.

    2. At the same time, the malfunction is stored in memory as a Diagnostic Trouble Code (DTC). When a Global TechStream (GTS) is connected to the DLC3, the DTC can be read. For details, refer to the Repair Manual.