System Description [09/2014 - 10/2015]

LANE-KEEPING ASSIST DESCRIPTION
1. The lane-keeping assist system uses the lane 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

SYSTEM OPERATION

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.

Lane Departure Warning Function Operation Suspension Condition	Restart Condition
When vehicle speed is less than 48 km/h (30 mph)	When vehicle speed is 48 km/h (30 mph)
When turn signal light switch is operated	When turn signal light switch is turned off
When steering force above a specified amount is applied	When steering force above a specified amount is not applied
When lane recognition camera sensor cannot detect lane marker	When lane recognition camera sensor can detect lane marker
After lane departure warning has been issued	When the vehicle is back to its lane, or a few seconds have passed since warning was executed

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.

Lane-keeping Assist Function Operation Suspension Condition	Restart Condition
Lane recognition camera cannot detect lane marker	Lane recognition camera sensor can detect lane marker
Vehicle speed is not within 72 to 180 km/h (45 to 112 mph)	Vehicle speed is within 72 to 180 km/h (45 to 112 mph)
Turn signal light switch is operated	Turn signal light switch is turned off
Windshield wiper switch is set to Hi	Windshield wiper switch Hi is turned off
Steering force above a specified amount is applied	Steering force above specified amount is not detected
Steering force above a specified amount does not occur*	Steering operation is detected
Lane change is performed	Driving within a lane is confirmed

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.
- Dynamic radar cruise control system is canceled*
- Lane-keeping assist main switch is turned off
- There is high temperature in the lane recognition camera's
- Lane 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.

FUNCTION OF MAIN COMPONENTS

Item	Outline
Lane recognition camera sensor assembly	Takes image of road in front, and sends it to lane recognition camera sensor assembly
Steering pad switch assembly (Lane-keeping assist main switch)	Turns lane-keeping assist system on / off
Windshield wiper switch assembly	Sends the operation condition of the windshield wiper switch and turn signal light switch signal to the driving support ECU.
Power steering ECU assembly	Based on signal from driving support ECU, steering force is applied Sends driver's steering operation information to driving support ECU
Brake actuator assembly	Receives buzzer operation signal from driving support ECU, and sends it to skid control buzzer. Sends vehicle speed information to driving support ECU
Yaw rate sensor	Detects yaw rate of vehicle and transmits its signal to driving support ECU
Combination meter assembly (LKA indicator light)	Turns on when lane-keeping assists switch is on
Combination meter assembly (Buzzer)	When lane-keeping assist system detects malfunction, warning buzzer sounds once to inform driver. When hands-free driving is detected, buzzer sounds twice to inform driver.
Combination meter assembly (Multi-information display)	When lane-keeping assist function is operating, steering wheel assistance is displayed in multi-information display to inform driver of control operation When lane-departure warning function is operating, lane marker are displayed to inform driver of lane detection When driving support ECU detects malfunction signal, multi-information display displays message to inform driver
Cruise control main switch	Turns cruise control system on / off
Stop light switch assembly	Detects depressing of brake pedal and transmits its signal to driving support ECU
Skid control buzzer	This buzzer sounds upon receiving signal from brake actuator assembly
Vehicle speed sensor	Sends vehicle speed signal to brake actuator assembly, and then it is sent to driving support ECU
Driving support ECU	Based on lane marker information and information from other functions, driving support ECU sends signals to electronic power steering ECU so that it applies steering force Controls multi-information display's display information and buzzer sound condition Monitors lane-keeping assist malfunctions, and records diagnostic information