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 the object recognition camera's image of the road in front to detect lane marker on either side of the vehicle. If the system detects that the vehicle is about to move out of the lane marker, it uses the warning buzzer and multi-information display to warn the driver.
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, the road surface is bright
Road has a reflective surface similar to concrete road
Area where brightness changes suddenly, such as entrances and exits of tunnels or similar area
Bright light is directed at sensor
Incline of the road varies, winding road or other type of road where road surface is irregular
Bad weather
Frozen or snowy roads
With water or other liquid on road surface
2. SYSTEM OPERATION
(a) Lane departure warning function:
The lane departure warning function operates when the lane-keeping assist main 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 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 main switch is on, the vehicle speed is approximately 72 to 180 km/h (45 to 112 mph), 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 occur, the lane-keeping assist function will stop operating. If the condition is not 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).
(c) During the lane-keeping assist system operation, if any of the following conditions is detected, the lane-keeping assist system will stop operating.
Dynamic radar cruise control system is canceled*
Lane-keeping assist main switch is turned off
object recognition camera's interior temperature is 65°C (149°F) or more
Object recognition camera sensor's interior temperature is -35°C (-31°F) or less
Electronic power steering system's operation limit is reached
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. FUNCTION OF MAIN COMPONENTS
