Lane Departure System: Description and Operation
CRUISE CONTROL: LANE-KEEPING ASSIST SYSTEM: SYSTEM DIAGRAM
Communication Table
SYSTEM DESCRIPTION
1. LANE-KEEPING ASSIST DESCRIPTION
(a) The lane-keeping assist system uses an image of the road from the lane-recognition camera sensor to detect the lane markers for the lane that the vehicle is in. If the system detects that the vehicle is about to move out of its lane, it uses the warning buzzer, multi-information display and steering assistance to warn the driver.
Text in Illustration
White lines
* The white lines indicate the condition of the lane keeping assist system.
i. Lines are not displayed: LKA main switch is off.
ii. Thin lines are displayed: Lane departure warning function is not operating.
iii. Thick lines are displayed: Lane departure warning function is operating.
Steering wheel
* When the steering wheel is displayed, this indicates that the lane keeping assist function is operating.
Radar cruise display
* Indicates operation conditions for radar cruise
Radar cruise set vehicle speed
* Indicates the set vehicle speed when the radar cruise is activated
However, in the following conditions, the lane-keeping assist system may not function normally.
Vehicle is near toll booths or similar areas
Road has no lane marker
Lane marker are cracked
Road has yellow lines
There is a shadow on either of the lane marker
As a result of reflections, road surface is bright
Road with reflective surface similar to concrete road
Area where brightness changes suddenly, such as entrances and exits of tunnels or similar area
Bright light directed at sensor
Incline of road varies, winding road or other type of road where road surface is irregular
Bad weather
Frozen or snowy roads
Road surface with water or other liquid
If the vehicle jounces up and down when driving on a bumpy road or while driving over expansion joints
When the head light lenses are dirty and the beams are dim or when the head lights are misaligned
2. SYSTEM OPERATION
(a) Lane departure warning function:
The lane departure warning function operates when the lane-keeping assist switch is on, the vehicle speed is 48 km/h (30 mph) or more, and lane markers on the road surface are detected. With the lane departure warning function operating, if the vehicle is about to move out of the lane and this is detected by the driving support ECU, the ECU uses the warning buzzer and the multi-information display to warn the driver. Also, the ECU uses the electronic power steering system's motor to apply steering force and give suggestions to the driver for lane departure avoidance.
HINT
This function only provides suggestions for lane departure avoidance. This function does not automatically move the vehicle within a lane.
(b) Lane-keeping assist function:
The lane-keeping assist function operates when the lane-keeping assist switch is ON, the vehicle speed is approximately 72 to 180 km/h (45 to 112 mph) and the dynamic radar cruise control system is ON. With the lane-keeping assist function operating, steering assistance is provided for the driver according to the driving conditions so that the vehicle stays near the midpoint of a lane. When the vehicle cannot be maintained within a lane and this is detected by the driving support ECU, the ECU uses the warning buzzer and the multi-information display to warn the driver. During the lane-keeping assist function operation, if any of the following conditions occurs, the lane-keeping assist function will stop operating. If the condition is no longer detected, the lane-keeping assist function will automatically start operating again.
HINT
*: This refers to situations where the vehicle is driven for 15 seconds or more on a lane that is straight; or 5 seconds or more on a curved road (curve radius 1000 m (3281 ft.) or less).
During the lane-keeping assist system operation, if any of the following conditions is detected, the lane-keeping assist system will stop operating.
* When lane-keeping assist switch is turned off
* When object recognition camera sensor's interior temperature is 70°C (158°F) or more
* When lane-keeping assist system is malfunctioning
HINT
During the lane-keeping assist function operation, if the dynamic radar cruise control system is canceled, the lane-keeping assist system will change from the lane-keeping assist function to the lane departure warning function.
3. LKA INDICATOR LIGHT
The LKA indicator light is built into the combination meter. It informs the driver of the operational condition or malfunctions of the lane keeping assist system.
4. FUNCTION OF MAIN COMPONENTS
