LANE-KEEPING ASSIST DESCRIPTION
The lane-keeping assist system uses the object recognition camera sensor's video 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, 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
SYSTEM OPERATION
Lane departure warning function:
The lane departure warning function operates when the lane-keeping assist switch is ON, the vehicle speed is approximately 50 km/h (31 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.
Tech Tips
This function only provides suggestions for lane departure avoidance. This function does not automatically move the vehicle within a lane.
Lane-keeping assist function:
The lane-keeping assist function operates when the lane-keeping assist switch is ON, the vehicle speed is approximately 70 to 170 km/h (43 to 106 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 cancel operating. If the condition is not longer detected, the lane-keeping assist function will automatically start operating again.
| Lane-keeping assist function operation cancel condition | Restart condition |
|---|---|
| When object recognition camera sensor cannot detect lane marker | When object recognition camera sensor can detect lane marker |
| When vehicle speed is not within 70 to 170 km/h (43 to 106 mph) | When vehicle speed is within 70 to 170 km/h (43 to 106 mph) |
| When turn signal light switch is operated | When turn signal light switch is turned OFF |
| When windshield wiper switch is set to Lo or Hi | When windshield wiper switch is turned OFF |
| When steering force above a specified amount is applied | When steering foru above specified amaunt is not ditected |
| When steering force above a specified amount does not occur* | When steering operation is detected |
| When changing lanes | When driving within a lane is confirmed |
Tech Tips
*: 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 function operation, if any of the following conditions is detected, the lane-keeping assist function will cancel operating.
When dynamic radar cruise control system is canceled*
When lane-keeping assist switch is turned OFF
When object recognition camera sensor's interior temperature is 65°C (149°F) or more
When object recognition camera sensor's interior temperature is -30°C (-22°F) or less
When electronic power steering system's operation limit has occurred
When driving with no hands on the steering wheel
When lane-keeping assist system is malfunctioning
Tech Tips
*: 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.
FUNCTION OF MAIN COMPONENTS
| Item | Outline |
|---|---|
| Object recognition ECU | Detects lane marker from object recognition camera sensor's video of road in front, and sends information to driving support ECU |
| Object recognition camera sensor | Takes video of road in front, and sends video signals to object recognition ECU |
| Steering pad switch assembly (Lane-keeping assist main switch) | Turns lane-keeping assist main switch ON / OFF |
| Combination switch | Sends signal to driving support ECU to cancel lane departure warning function |
| Power steering ECU |
|
| Skid control ECU |
|
| Suspension control ECU | Detects vehicle height condition, and sends information to driving support ECU |
| Steering angle sensor | Detects driver's steering torque and transmits its signal to power steering ECU |
| Yaw rate sensor | Detects yaw rate of vehicle and transmits its signal to driving support ECU |
| No. 1 meter ECU sub-assembly (LKA indicator light) |
|
| No. 1 meter ECU sub-assembly (Warning buzzer) | When lane-keeping assist system detects malfunction, warning buzzer sounds once to inform driver |
| No. 1 meter ECU sub-assembly (Multi-information display) |
|
| Cruise control main switch | Turns cruise control system ON / OFF |
| Stop light switch | Detects depressing of brake pedal and transmits its signal to driving support ECU |
| Skid control buzzer | This buzzer sounds upon receiving signal from skid control ECU |
| Vehicle speed sensor | Sends vehicle speed signal to skid control ECU, and then it is sent to driving support ECU |
| Driving support ECU |
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