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System Description

  1. GENERAL 
    1. The parking assist ECU uses vehicle condition signals from the steering angle sensor, power steering ECU, skid control ECU, ECM, etc. to make calculations and estimates. These results are used to make various guidelines, which are combined together with video from the television camera, and output to the multi-display. Also, control signals are output to each ECU and the advanced parking guidance system's various controls are performed.
    2. This system has a television camera to display the rear view of the vehicle on the multi-display. The display panel also shows a composite view consisting of the rear view and parking guidelines to assist the driver with parking the vehicle.
    3. This system is equipped with a self-diagnosis system, which is operated on a designated window that appears on the display panel, just as in the navigation system.
  2. FUNCTION OF COMPONENTS 
    1. The parking assist ECU controls the system by using information from the following components.
      FUNCTION CHART

      Components Function
      Television Camera
      • Mounted on the luggage compartment door to transmit the rear view of the vehicle to the parking assist ECU.
      • A color video camera that uses a CCD (Charge Coupled Device) and a wide-angle lens.
      Parking Assist ECU Receives vehicle condition signals from various ECUs, makes frame based on calculations, combines the frame with video from the television camera, and outputs the video with frame to the multi-display. Also, control signals are output to each ECU and the advanced parking guidance system's various controls are performed.
      Multi-display Receives video signals containing a composite of the rear view of the vehicle and the frame signals from the parking assist ECU, and displays them on the display panel.
      Display and navigation
      • Uses the yaw rate detected by the gyro sensor that is built into the navigation ECU to transmit the movement of the vehicle to the parking assist ECU.
      • Transmits the status of the language settings, which is selected by the language selector of the navigation screen display, to the parking assist ECU.
      Steering Angle Sensor Detects the angle of the steering wheel and sends the resulting signals to the parking assist ECU through CAN communication.
      ECM Transmits the shift position signal received from the park/neutral position switch to the parking assist ECU, via the CAN communication.
      Park/Neutral Position Switch Transmits a received shift position signal to the ECM.
      Skid Control ECU Sends stop switch, parking switch, vehicle speed, driving distance, and other vehicle condition signals to the parking assist ECU. Also receives advanced parking guidance failure signals and buzzer activation signals, and sounds the buzzer.
      Power Steering ECU Sends EPS failure, intervention steering, and other related vehicle condition signals to the parking assist ECU. Also, based on advanced parking guidance control signals and steering-related signals, performs steering control.
      Front Speaker RH Receives audio signals from the parking assist ECU, and outputs voice guidance according to the mode.
  3. OPERATION EXPLANATION 
    1. The ECM, through the CAN communication system, input the R position signal from the park/neutral position switch to the parking assist ECU when the shift lever is moved to the R position. After receiving the R position signal, the parking assist ECU switches the display signal for the multi-display from the navigation system to the advanced parking guidance system.
  4. COMMUNICATION SYSTEM OUTLINE 
    1. This advanced parking guidance system communicates between its components by AVC-LAN. Also, "PARALLEL PARKING ASSIST MODE" judges the vehicle angle data transmitted via AVC-LAN from the navigation ECU (the data is calculated by the navigation ECU by integrating the yaw rate of the gyro built into the navigation ECU).
    2. If a short circuit or open circuit occurs in the AVC-LAN circuit, communication is interrupted and the advanced parking guidance system will stop functioning.
  5. DIAGNOSTIC FUNCTION OUTLINE 
    1. This advanced parking guidance system has a diagnostic function (displayed on diagnosis menu on display).
  6. MULTI-DISPLAY OUTLINE 
    1. Touch switch

      Touch switches are touch-sensitive (interactive) switches operated by touching the screen. When a switch is pressed, the outer glass bends into contact the inner glass at the pressed position. By doing this, the voltage ratio is measured and the pressed position is detected.

      Fig 1: Identifying Touch-Sensitice Switch Position With Position On Screen
      G04948842Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. AVC-LAN DESCRIPTION 
    1. What is AVC-LAN?

      AVC-LAN, an abbreviation for "Audio Visual Communication Local Area Network", is a united standard developed by the manufacturers in affiliation with Toyota Motor Corporation. This standard pertains to audio and visual signals as well as switch and communication signals.

      Fig 2: AVC-LAN Communication Diagram
      G04951900Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Purpose:

      Recently, car audio systems have rapidly developed and the functions have vastly changed. The conventional car audio system is being integrated with multimedia interfaces similar to those in navigation systems. At the same time, customers are demanding higher quality from their audio systems. This is merely an overview of the standardization background. The specific purposes are as follows:

      1. To solve sound problems, etc. caused by using components of different manufacturers thorough signal standardization.
      2. To allow each manufacturer to concentrate on developing products they do best. From this, reasonably priced products can be produced.

        HINT:

        • If a short +B or short to ground is detected in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.
        • The multi-display is the master unit.
  8. NOTES FOR ADVANCED PARKING GUIDANCE 
    1. Notes for advanced parking guidance.
      1. The advanced parking guidance may not function properly if subjected to a severe blow by any hard object.
      2. Do not "scrub" the cover part of the camera (resin made). Scrubbing it may scratch the cover and affect the image. Prevent organic solvents, waxes, bond removing solvents, or glass coating from adhering to the cover. Clean it off immediately, and wash with water.
      3. Exposing the camera to sudden temperature changes may affect proper function.
      4. A clear image may not appear if the camera is dirty with snow, mud, etc. In that case, wash with water and wipe off the water. Use a detergent to remove dirt if necessary.
    2. Images are difficult to discern even in normal conditions if:
      1. Camera screen is frosted over (the image immediately after turning the engine switch to the on position may be blurred or darker than normal).
      2. A strong beam of light, such as a sunbeam or headlight, hits the camera.

        HINT:

        When a strong light, such as a sunbeam reflected off a vehicle's body, hits the camera, the image may be blurred. This is called the "SMEAR" phenomenon, peculiar to the CCD camera.

      3. It is too dark around the camera (at night, etc.).
      4. The ambient temperature around the camera is either too high or too low.
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