ROAD SIGN ASSIST SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


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

      Component Function
      Forward Recognition Camera Monocular Camera Captures road signs
      Forward Recognition Camera ECU

      • Performs RSA system control based on information of road signs captured by the monocular camera.

      • Transmits an operation signal to the camera heater.*1
      Camera Heater (Forward Recognition Hood with Heater Sub-assembly)*1 The camera heater is heated according to signals from the forward recognition camera.
      Millimeter Wave Radar Sensor Assemnly Radiates millimeter waves forward, uses the reflected waves to detect the presence of an object, and then transmits this information to the forward recognition camera.
      Skid Control ECU Sends a vehicle speed signal from the speed sensor to the forward recognition camera.
      Steering Pad Switch Assembly Meter Control Switches Sends a multi-information operating signal to the forward recognition camera.
      Combination Meter Assembly

      • Outputs turn light signal commands, which are sent from the headlight dimmer switch assembly, to the forward recognition camera.

      • Sends an ambient temperature signal to the forward recognition camera.
      Combination Meter Assembly Buzzer Sounds for speed limit is exceeded or no overtaking notifications.*2
      Multi-information Display

      • Displays road signs recognized by the forward recognition camera.

      • The RSA system can be turned on and off through the settings tab.
      Hybrid Vehicle Control ECU Sends a shift position signal to the forward recognition camera.
      Center Airbag Sensor Assembly Detects the yaw rate and sends it to the pre-crash safety city sensor (forward recognition camera).
      Central Gateway ECU Relays the data between the each CAN buses.
      Speed Sensors Detect the wheel speed of each of the 4 wheels and sends it to the skid control ECU.
      Air Conditioning Amplifier Assembly Sends the outside air temperature to the forward recognition camera.
      Main Body ECU (Multiplex Network Body ECU) Sends country specification information signals to the forward recognition camera.

      Tech Tips

      *1: Models with camera heater

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

  2. FUNCTION


    1. The RSA system recognizes the following traffic signals using the forward recognition camera

      Category Sign Type Example of Recognizable Traffic Sign
      Speed limit Round maximum speed limit/End of speed limit B00208E
      No overtaking No overtaking/End of no overtaking B00209W
      Supplemental signs Road condition signs Ramp way B00208X
      Rain B00208Z
      Ice B002086
      Wet B0020AA
      End of prohibition B002093

    2. The RSA system recognizes the following traffic signals using the forward recognition camera.

      Category Display Example Details
      Speed limit related B00207S

      • 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 B00207Y 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.) B002093 Informs the driver when all applicable prohibitions, such as speed limit and no overtaking, have ended.
      Speed limit with supplemental sign related Ramp way B00209M 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 B00207U Informs the driver of the maximum speed limit on the currently driven road when it is raining or the road surface is wet.
      Ice B00207W Informs the driver of the maximum speed limit on the currently driven road when there is accumulated snow or ice.
      Blank B00209Z The display is blank when the system is unable to recognize a supplemental sign.

    3. Notification functions are used in the RSA system which inverts 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 (3 mph) and the speed limit sign is 60 km/h (37 mph), the colors of the displayed sign are inverted when the actual vehicle speed exceeds 65 km/h (40 mph). 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 forward recognition camera. 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 B00208P

      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
        Inverted Display B00208I

  3. SYSTEM CONTROL


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

    2. A customization function is used for the RSA system, 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 forward recognition camera 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.

        B00209GE01
        *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 power switch is turned to on (IG) again.

        B002084E02
        *1 Power Switch is Turned Off
        *2 Power Switch is Turned to 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.

        B0020A9E01
        *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 forward recognition camera cancels the RSA system, 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). For details, refer to the Repair Manual.