ROAD SIGN ASSIST SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


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

      Component Function
      Pre-crash Safety City Sensor Monocular Camera Captures road signs.
      Pre-crash Safety City Sensor 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 (Pre-crash Safety City Heater)*1 The camera heater is heated according to signals from the pre-crash safety city sensor.
      Skid Control ECU Sends a vehicle speed signal from the speed sensor to the pre-crash safety city sensor.
      Main Body ECU (Instrument Panel Junction Block Assembly) Send vehicle specification information to the pre-crash safety city sensor.
      Air Conditioning Amplifier Assembly Sends an ambient temperature signal to the pre-crash safety city sensor.
      ECM Sends a shift position signal to the pre-crash safety city sensor.
      Combination Meter Assembly Outputs turn signal commands, to the pre-crash safety city sensor.
      Combination Meter Assembly Multi Buzzer Sounds for speed limit exceeded and no overtaking notifications.*2
      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.
      Steering Pad Switch Assembly Sends a multi-information operating signal to the pre-crash safety city sensor.

      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 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 A004M4E
      No Overtaking No Overtaking/End of No Overtaking A004LRD
      Supplemental Signs Road Condition Signs Ramp Way A004LOX
      Rain A004LU2
      Ice A004LZC
      All Canceled (All restrictions canceled. Return to default road regulations.) A004MFD

    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 A004LYA

      • 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 A004M5L 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.) A004MFD Informs the driver when all applicable prohibitions, such as speed limit and no overtaking, have ended.
      Speed Limit with Supplemental Sign Related Ramp Way A004LTP 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 A004MDQ Informs the driver of the maximum speed limit on the currently driven road when it is raining or the road surface is wet.
      Ice A004LUA Informs the driver of the maximum speed limit on the currently driven road when there is accumulated snow or ice.
      Blank A004LP0 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. 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 A004MG8

      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 A004MDZ

  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.

        A004LRZE02
        *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.

        A004MBYE02
        *1 Ignition switch is off
        *2 Ignition switch is turned ON
        *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.

        A004MA1E02
        *1 Road Sign Recognized
        *2 Sign Display Off
        *3 Sign Display On

  4. CONSTRUCTION


    1. Pre-crash Safety City Sensor


      1. The pre-crash safety city sensor is composed of a monocular camera and pre-crash safety city sensor ECU.

      2. The RSA is controlled by the monocular camera and pre-crash safety city sensor ECU.

        A004MFME02
        Text in Illustration
        *1 Monocular Camera *2 Pre-crash Safety City Sensor (with Built-in Pre-crash Safety City Sensor ECU)
        *a Monocular Camera Recognition Range (70 m (230 ft.)) *b The illustrations shown are examples only.

      3. Monocular Camera


        1. Road signs captured by the monocular camera are output to the pre-crash safety city sensor ECU.

        2. The pre-crash safety city sensor ECU judges road signs recognized by the monocular camera and displays information based on these judgments on the multi-information display.

          A004MJKE02

      4. When one of the following operations is conducted, the pre-crash safety city sensor angle must be adjusted. For details, refer to the Repair Manual.


        1. The pre-crash safety city sensor is removed and reinstalled or replaced.

        2. Parts relating to the tire or suspension are replaced or adjusted

        3. Strong force is applied onto the pre-crash safety city sensor.

    2. Camera Heater (Pre-crash Safety City Heater) (Models with Camera Heater)


      1. The camera heater, which is installed between the pre-crash safety city sensor and windshield glass, is heated according to signals from the pre-crash safety city sensor in order to prevent the windshield glass on the front of the pre-crash safety city sensor from fogging, and also to remove fog buildup. For details, see the PRE-CRASH SAFETY section.

  5. OPERATION


    1. Combination Meter


      1. The combination meter assembly displays recognized signs on the multi-information display based on information of road signs recognized by the pre-crash safety city sensor.

      2. The RSA system display mode can be selected by switching the display mode of the multi-information display through operation of the multi-information switch in the steering pad switch assembly.

      3. When the driving assist system information tab is selected for display on the multi-information display, road signs recognized by the pre-crash safety city sensor are displayed on the upper portion of the multi-information display.

      4. A maximum of 3 signs can be displayed simultaneously. When 3 signs are displayed, the signs are displayed in the following order from left to right: speed limit related, speed limit with supplemental sign related and no overtaking related.

        A004M96E03
        Text in Illustration
        *a Speed Limit Related *b Speed Limit with Supplemental Sign Related
        *c No Overtaking Related *d The illustration shown is an example only. The illustration may differ from the actual vehicle screen.

      5. When an information tab other than the driving assist system information tab is selected for display on the multi-information display, road signs recognized by the pre-crash safety city sensor are displayed as pop-ups on the lower center portion of the multi-information display. Furthermore, the pop-up display is only for speed limit signs. It is not displayed for no overtaking signs and speed limit with supplemental signs.

        A004MI6E02
        Text in Illustration
        *a Speed Limit Related *b Multiple Road Signs Recognized
        *c The illustrations shown are examples only. The illustrations may differ from the actual vehicle screens. - -

      6. When there is a malfunction in the RSA system or the system is temporarily unusable, a warning message is displayed on the multi-information display, the master warning light illuminates and the multi buzzer sounds.

        Condition Multi-information Display Master Warning Light Multi Buzzer
        System Malfunction Check RSA system Illuminates Sounds
        Pre-crash Safety City Sensor Temperature High Front Sensor Systems are Temporarily Unavailable Due to Inappropriate Temp. Wait a Moment.* - -
        Windshield Glass Dirty or Fogging Front Camera Vision Blocked Clean and Demist Windshield* - -

        Tech Tips

        *: The message appears for 6 seconds on the multi-information display.

  6. DIAGNOSIS


    1. If a malfunction is detected in the RSA the pre-crash safety city sensor cancels the RSA, sounds the multi 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.