Table of Contents Lane Departure Warning Subject Page Introduction .5 Display and Control Concept.6 Head-up Display (HUD) .8 Systems Overview .9 Functions .12 One Function, One Control Unit.12 Lane Detection .13 Roadway Markings.14 Road Situations.15 Environmental Conditions.18 Physical Limitations .20 Availability of the Lane Departure Warning.22 Warning Output.22 Warning Point .22 Warning Duration .23 Suppression ofthe Warning.23 System Components.24 Lane Departure Warning Control Unit.26 Installation Location .27 Overvoltage/Undervoltage Behavior.27 Wake-up.27 Sleep Mode.27 Lane Departure Warning Camera.28 Colored or Black Roadway Marking .28 Camera Size.30 Camera Objective .30 Vibration Motor .30 Windscreen.31 Button .31 Other Control Units.31 Steering Column Switch Cluster.31 Car Access System .31 Instrument Cluster/Head-up Display.31 Initial Print Date: 04/07 Revision Date: Subject Page Body Gateway Module .31 Other Components.32 Mirror Caps, Cable Finisher, Headlining.32 Mirror Base With High Beam Assistant .32 Service Information. .33 Calibration.33 Diagnosis.35 Check Control Message .35 Lane Departure Warning Model: E60.E61 Production: From 3/2007 Production Model: E63, E64 Production: From 9/2007 Production After completion of this module you will be able to: • Explain the operation of the Lane Departure Warning System • Identify the Components used in the Lane Departure Warning System • Understand the operation of the camera 4 Lane Departure Warning Introduction The lane departure warning is available to orderfrom 03/07 as option 5AD forthe E60 and E61.The feature will be introduced in 09/07 on the E63 and E64. Fatigue or inattentiveness on the road can cause a driverto unintentionally leave a lane. This could result in the vehicle driving into a lane with oncoming traffic or ditches at the side of the road. BMW's lane departure warning is a driver assistance system designed to inform the dri¬ ver in good time of unintentional course deviations by means of vibrations in the steering wheel intended to prompt the driverto make corrective steering movements. The lane departure warning is a driver assistance system. The area in front of the vehicle is captured by a camera. This makes it possible forthe roadway markings to the right and left of the current lane to be detected. If the vehicle approaches a roadway marking in the absence of a turn indication, the dri¬ ver is informed of the course deviation by steering wheel vibrations before the vehicle crosses the line. The camera is fitted near the rear-view mirror behind the windscreen and its camera images to the control unit on a data line. The control unit contains the software that determines the position of the vehicle in the lane from the camera images. The lane departure warning is designed for operation on highways, major roads and well maintained country roads. A warning is issued if the system (current driving conditions within a specific time frame being equal) detects that the vehicle is crossing the roadside border line. The warning can be felt as a vibrating of the steering wheel. The lane departure warning is switched on and off using a button on the steering wheel. When the ignition is switched on, the lane departure warning system always reverts to the state that was active when the vehicle was last switched off (last function mode). The display indicating whether the lane departure warning is switched on or off is output by the instrument cluster or, optionally, by the head-up display. When the lane departure warning is switched on, there is an additional display indicating whetherthe system is primed or not. Note: The system is only primed if it is switched on and has detected one or two roadside borderlines with the vehicle travelling at a speed faster than 70 km/h. 5 Lane Departure Warning Display and C ontrol C oncept The lane departure warning is switched on and off using the button shown below on the multi-function steering wheel. The lane departure warning is switched on and off with each press of the button. When the ignition is switched on, the lane departure warning system always reverts to the state that was active when the vehicle was last switched off (last function mode). Lane departure warning button E60/E61 Index Explanation Index Explanation 1 Lane departure warning button 2 Vibration motor 6 Lane Departure Warning The system function display in the instrument cluster can take the form of the states list¬ ed in the following table. Displays in the instrument cluster Lane departure Left-hand, right-hand lane or both lanes detected and v > 70 warning ON km/h Display in the instrument cluster with ACC deactivated Note: If the vehicle has Active Cruise Control AC C, the lane departure warning display is combined with the ACC symbol. Display in the instrument cluster with ACC activated Note: When the AC C display is shown depends on the driving situation. The display of the states listed above is the same for the head-up display. Displays in the head-up display Lane departure warning ON Shown here without the ACC symbol. Left-hand, right-hand lane detected or both lanes detected and v > 70 km/h |\ ■ FRANKFURTER sy IRING U U 2000 m 75 Shown here with the ACC symbol. Note: There is an option to switch the lane departure warning display in the head-up display on or off on the Central Information Display using the controller. 7 Lane Departure Warning The lane departure warning can be switched on as of terminal 15 ON. The system is available from a speed of 70 km/h.The lane departure warning will also be primed if lanes are detected. If the lane departure warning is switched on at speeds of under 70 km/h, a message will appear in the instrument clusterfor3 seconds indicating availability above a speed of 70 km/h. Head-up Display (HUD) It is possible to activate or deactivate the lane departure warning display in the Head-up Display using the controller. The activation option is located in the Head-up Display menu > Head-up Display display options. Select "ACC/lane departure warning" and confirm with the controller. hud* t> * Artzeigi$n Head-Up Display » □ ACC f Spurverlassenswamung □ Check-Controi“Me!dungeFi □ M-Artsicht BAYERN3 TP TMC « 'i.iil 10:42 Message indicating the availability of the lane departure warning. HUD menu > Head-up Display display options E60 8 Lane Departure Warning Systems Overview D[ h -J AJ\ fcbasi ■ TLC i vu£ F- CAW m KflM WLP SAS Index Explanation Index Explanation 1 Lane departure warning camera 8 Car Access System 2 Lane departure warning control unit 9 Instrument cluster/head-up display 3 Vibration motor 10 Body gateway module 4 Multi-function steering wheel K-CAN BodyCAN 5 Lane departure warning button PT-CAN Powertrain CAN 6 Volute spring cassette W-UP Wake-up 7 Steering column switch cluster Lane departure warning system overview The lane departure warning system receives a number of input signals. The image data of camera (1) is evaluated in lane departure warning control unit (2) together with the other vehicle data that the control unit receives on the PT-CAN.The lane departure warning is realized from the combination of this data. Instrument cluster (9) and head-up display (9) output the displays of the lane departure warning. Electric motor (3) in multi-function steering wheel (4) produces the vibration of the steer¬ ing wheel by means of an imbalance mass. Body gateway module (10) transfers the PT-CAN messages from the lane departure warning control unit to the K-CAN and vice versa. 9 Lane Departure Warning System Schematic Circuit Diagram 10 Lane Departure Warning Index Explanation Index Explanation 1 Head-up display HUD 12 Volute spring cassette 2 Lane departure warning camera 13 Steering column switch cluster SZL 3 Rain/light sensor RLS 14 CarCommunication ComputerCCC 4 Dynamic Stability Control (DSC) 15 Instrument cluster Kombi 5 Body gateway module 16 Light module LM 6 Lane departure warning control unit K-CAN Body CAN 7 Central Information Display CID PT- CAN Powertrain CAN 8 Controller MOST Media Oriented System Transport 9 Fuse in the rear distribution box LVDS Low Voltage Differential Signalling 10 Vibration motor KL 30g Terminal 30 switched 11 Lane departure warning button Camera (2) sends image data to lane departure warning control unit (6) on the LVDS data line. The control unit receives vehicle data on the PT-CAN.The vehicle data includes the sta¬ tus of the turn signal steering column switch or the button for the lane departure warning, for example. Instrument cluster (15) is able to display whether or not the lane departure warning sys¬ tem is switched on. The primed status or availability of the lane departure warning system is also displayed in the instrument cluster. Using controller (8), it is possible to select an option to have the information displayed in head-up display (l).The relevant menu appears in Central Information Display (7). 11 Lane Departure Warning Functions One Function, One Control Unit The lane departure warning system receives a number of input signals. Details of the input and output signals evaluated by the lane departure warning system are listed below. Input and output signals Input signal Sensor control unit Explanation Steering wheel angle Dynamic Stability Control steering column switch cluster steering angle sensor Lane detection assistance Brake pressure Dynamic stability control Brake pressure threshold as warning cancellation criterion Road speed Dynamic stability control Lane detection assistance Road speed Instrument cluster Control of the primed status display Terminal status Car Access System Control of the operating states of the lane departure warning control unit Vehicle identification number Car Access System Detection as to whether the control unit fitted and the camera match the vehicle Engine status Digital Motor Electronics/ Digital Diesel Electronics Activation of the processor for image processing after the engine start Lane departure warning button Steering column switch cluster System switch on/off Direction indicator Steering column switch cluster Suppression of warnings in case of intentional lane departure Wiper status Steering column switch cluster Support of lane detection by detection of when the windscreen wiper sweeps through the camera image Battery voltage Instrument cluster Fault code memory Kilometre reading Instrument cluster Fault code memory Output signal Sensor control unit Explanation Lane departure warning Instrument cluster Head-up display Display of status and primed status in the instrument cluster and head- up display Check control message Lane departure warning control unit Request of the Check Control message 12 Lane Departure Warning Lane Detection The camera is fitted to the windscreen near the rear-view mirror. The camera captures the roadway up to approximately 40m to the front of the vehicle and up to approximately 5 m to the right and left. Using image processing technology, the lane departure warning control unit looks for possible lane markings in the images captured by the camera. The software in the control unit also checks which lane markings are delimiting the current lane in which the vehicle is driving. From the detected lane markings, the lane departure warning is then calculated for the vehicle. 13 Lane Departure Warning Roadway Markings The roadway markings in the image may differ greatly depending on the type of road, environmental conditions or country. The system is able to detect various types of road¬ way marking in a number of situations. Type of Roadway Marking Explanation Broken Lines Unbroken Lines Double Lines Bott's Dots "Car Pool" Lanes 14 Lane Departure Warning Road Situations The lane departure warning is able to handle various road situations. Type of Roadway Marking Explanation Roads with only a Center Line (edge of road on left- hand side not detected) Roads without Center Line Highway Exit Highway Access Turn-off 15 Lane Departure Warning Type of Roadway Marking Explanation Hatched Zones S hoit B reaks in the M arking 16 Lane Departure Warning 17 Lane Departure Warning Environmental Conditions The lane departure warning functions under different environmental conditions. Type of Roadway Marking Explanation Rain/wet Asphalt Night Low-Level Sun Snow 18 Lane Departure Warning Type of Roadway Marking Explanation Light Colored Asphalt Dark Asphalt Tar Seams on the Road Oncoming Vehicles 19 Lane Departure Warning Physical Limitations Systems functionality may be restricted under various road and environmental conditions due to physical limitations. Type of Roadway Marking Explanation Construction Sites On roads with worn, poorly visible or inadequately painted lane markings. On roads with colored or black lane markings On roads on which the lane markings are covered by water, dirt, snow or ice. On roads with sharp bends. 20 Lane Departure Warning Type of Roadway Marking Explanation On roads with no distinct lane markings On roadways that are too narrow If the vehicle comes too close to a vehicle in front that the camera is unable to see the lane markings within the detection range. If the view of the camera is blocked by dirt, snow, ice or other obstructions on the windscreen. In very poor weather conditions (rain, fog, snow, etc.) If intense light shines into the camera from the front orfades out the lane markings. 21 Lane Departure Warning Availability of the Lane Departure Warning The system is available when: • No system fault is present. • The lane departure warning system is calibrated correctly. • The vehicle speed is above the activation threshold (see following table). • At least one roadway marking has been detected by the system with sufficient certainty. • The vehicle is not in a construction site area with several possible roadway markings. • The vehicle is on a road with an average lane width of more than 2.5 m. The speed threshold above which the lane departure warning can be available has been adapted to country-specific conditions. In the US the activation threshold is 45 mph and deactivation threshold is 42 mph. Warning Output The lane departure warning function only outputs a warning to the driver if the system is switched on and available. Warning Point The system outputs the warning to the driver if the driver approaches a detected roadway marking. To do so, the system calculates the anticipated time (t) before the roadway marking is crossed.The warning is output in time before the vehicle crosses the marking. Since warning situations may arise more frequently on narrow roads, the warning is out¬ put later by tendency on these kinds of road Warning output of the lane departure warning E60 Index Explanation Index Explanation 1 Current Lane t Calculated time before pointX 22 Lane Departure Warning Warning Duration The warning ends when: • The driver steers back into the lane. • A lane change is completed. • The vehicle drives on the line for longer than 2.5 s. • The turn signal is operated. • The brake pedal is depressed with force (brake-pressure-dependent). Note: A warning is output only once on approach to a roadway marking. The warning lasts no more than 2.5 s. If the vehicle remains on the line, no new warning will be issued. A new warning can only be issued if the vehi¬ cle has been steered back into the lane orthe vehicle has completed a change of lane. Suppression of the Warning A warning is suppressed despite the display of primed status if the following conditions exist on one side: • Turn signal operated before the vehicle is driven towards the warning trigger. • One-touch turn signal indicated on the side from which a warning would be triggered. There is no warning suppression if the hazard warning flashers are switched on. 23 Lane Departure Warning System Components The most important components for the lane departure warning are: • Lane departure warning control unit • Lane departure warning camera • Vibration motor in the multi-function steering wheel • Windscreen • Button • Low Voltage Differential Signalling line • Other control units - Steering column switch cluster SZL - Car Access System - Instrument cluster/head-up display - Body gateway module • Other components - Mirror caps - Cable finisher - Headlining - M irror base with high beam assistant 24 Lane Departure Warning Component Overview (example of E61) Index Explanation 1 Lane departure warning button 2 Lane departure warning camera 3 Panorama glass sunroof control unit 4 Lane departure warning control unit 5 Control unit holder 6 CD changer 7 Body basic module 8 Body gateway module 9 Comfort Access 25 Lane Departure Warning Lane Departure Warning Control Unit The control unit is accommodated in a 2/3 shell-type housing. For EMC reasons, the housing is made entirely of aluminum. It has two connectors: • 12-pin connection to the vehicle electrical system • 10-pin connection to the LVDS line. Index Explanation 1 LVDS Connection 2 Vehicle Electrical System Connection The control unit has two processors. One processor is for communicating with the vehi¬ cle electrical system on the PT-CAN.The second processor is used to calculate the lane departure warning. The communication processor is activated as soon as terminal 30g is ON. Messages can now be sent and processed on the PT-CAN. The control unit itself is still in sleep mode. From terminal 15 ON, the control unit reports to the vehicle electrical system on a cyclical basis. The control unit only becomes operational once the Engine running signal is pre- sent.This is because it is only at this point that the high-performance computer, whose responsibilities include image processing, is activated. The high-performance computer evaluates the image data of the camera together with the other vehicle data that the control unit receives on the PT-CAN.The lane departure warning is realized from the combination of this data. During operation of the wipe/wash system, the sweep of the wiper blades also takes them through the field of view of the lane departure warning's camera. Forthis reason, the con¬ trol unit for the lane departure warning receives information about whether the wipe/wash system is switched on or off. 26 Lane Departure Warning Installation Location The control unit is secured by a bracket to the support tube above the glove compart¬ ment. Overvoltage/Undervoltage Behavior The voltage range in which the control unit operates is 9.0 V to 16.0 V. Wake-up The control unit for the lane departure warning is woken by the wake-up signal of the control units on the PT-CAN. Sleep Mode In sleep mode, the control unit is switched off. 27 Lane Departure Warning Lane Departure Warning Camera The camera is fitted behind the windscreen at the base of the rear-view mirror. The cam¬ era for the lane departure warning captures the surrounding area, and therefore the lane markings, to the front of the vehicle. The camera's scope of detection ranges from approximately 4 m to 40 m ahead of the vehicle. The camera has a horizontal aperture angle of approximately 50°, and a vertical aperture angle of approximately 30°. Detection range of the lane departure warning camera using the E60 as an example The camera is a digital black/white CMOS camera. This means that the captured sur¬ roundings are output as a grayscale image. Colored or Black Roadway Marking Roadway markings Colored yellow, blue, red or black are also represented in grayscale. The grayscale image may stand out poorly, or not at all, from the grey road surface. In unfavorable situations, this could mean that these lanes cannot be detected. Note: If no lane is detected, the lane departure warning does not display primed status. 28 Lane Departure Warning Lane detection with the eye Lane detection with the camera 29 Lane Departure Warning TED6#7» Camera Size The graphic below illustrates the size of the camera by comparison with the vehicle's remote control. Index Explanation 1 Camera 2 Lens Shade 3 LVDS Connector Camera Objective The camera objective has several glass lenses. They are coated to diminish or even fully eliminate scattered light and thereby increase the image quality of the camera. Vibration Motor The vibration motor and its electronics are fully integrated inside the steering wheel. The vibration motor is fitted in the six o'clock spoke of the steering wheel. To generate the vibration, there is a small imbalance mass on the shaft of the vibration motor. The vibration motor is controlled directly by the control unit. The electronics in the steering wheel are used to convert the control voltage supplied by the control unit into the voltage value required by the motor and to provide its stabilization. The control voltage corresponds to the on-board voltage. The motor with imbalance mass issues a warning if the vehicle threatens to leave the current lane by causing the steering wheel to vibrate. Index Explanation 1 Vibration Motor 2 Imbalance mass 3 LVDS Connector 30 Lane Departure Warning Windscreen The lane departure warning requires a windscreen matched to the system.The wind¬ screen has a wider, black print that conceals the camera and a camera holder bonded on. Button The SZL records the requests input at the button and sends them to the lane departure warning control unit on the PT-CAN. Other Control Units Steering Column Switch Cluster The vibration motor in the steering wheel is connected directly to the lane departure warning control unit by the SZL and the slip ring. All steering wheels equipped with steering wheel heating LHZ require an SZL with steer¬ ing wheel heating.These SZLs are compatible with the lane departure warning. For steering wheels without LHZ, there is a special variant of the steering column switch clusterforthe lane departure warning. Car Access System The CAS control unit controls the wake-up line and thus also the waking of the control unitforthe lane departure warning. Instrument C luster/Head-up Display The instrument cluster and the head-up display display the activation status when the lane departure warning is switched on. Note: The message indicating availability of the lane departure warning is only displayed in the instrument cluster. A corresponding Check Control message is displayed in the event of a fault anywhere in the lane departure warning system. Body Gateway Module The body gateway module transfers messages from the lane departure warning control unit (PT-CAN) to the K-CAN.The same applies in the opposite direction. 31 Lane Departure Warning Other Components MirrorCaps, Cable Finisher, Headlining The lane departure warning system has wider mirror caps to conceal the camera, a cable finisher and a larger headlining cutout. Mirror Base With High Beam Assistant When fitted in combination with the high beam assistant (FLA), the system has a special mirror base for package reasons. Index Explanation 1 Headlining cutout with cable end 2 Rain/light sensor 3 Condensation sensor 4 Lane departure warning camera 5 M irror caps/high beam assistant 32 Lane Departure Warning Service Information Calibration If the system is to be able to calculate the distance to a given roadway marking, it must know the exact installation position of the camera on the one hand, and the camera's exact focal direction on the other. Due to installation tolerances and tolerances inside the camera, the position of the cam¬ era's viewing angle may vary by several degrees. The exact installation position of the camera and its installation angle are determined during calibration of the system and stored in the system. In production, there is a dedicated calibration bench for this process that determines the measured variables by means of sample boards, which are arranged in a defined posi¬ tion relative to the vehicle. Any replacement of the camera or windscreen requires a calibration of the system because the position of the camera and thus of the system sensor may have changed. No calibration is required if the control unit is replaced. In this case, the calibration data stored in the camera is transferred to the control unit and stored there. Each time the system is started, a check takes place to determine whether the system is calibrated and whether the system components are matched to each other and the vehi¬ cle. In this regard, the Vehicle Identification Number VIN stored in the control unit is com¬ pared with that of the vehicle's. With this plausibility check, it can be determined whether the control unit is coded cor¬ rectly and whether it belongs to the vehicle. The VIN stored in the camera is then compared with the VIN stored in the control unit. If discrepancies are detected, the system detects that a camera requiring new calibration has been fitted and it outputs a corresponding fault code. For more details, please refer to the BMW diagnostic system or the repair instructions. Note: A windscreen replacement cannot be detected by the system. In this case, the aftersales service organization is responsible for ensuring that the system is newly calibrated. 33 Lane Departure Warning To have the system calibrated in the aftersales service organization, a diagnostics job is started. This diagnostics job investigates whether the camera is functional and has free line of sight. This is determined from the detection of movements in front of the camera. Free line of sight can be determined by having someone walk by in front of the camera, for example. Calibration starts automatically on successful completion of this test step (good camera image). Calibration takes place during a calibration run, which can be carried out by the customer. In the event that the camera test failed, the calibration process is terminated and must be restarted afterthe possible interfering factors have been remedied. A specially developed algorithm is used for calibrating the system during the calibration run. This algorithm scans the image for all straightedges and, from their orientation, determines the viewing angle of the camera. The calibration algorithm works from a speed of 30 km/h. Forevaluation purposes, it essentially uses images captured during straight-ahead travel. As soon as enough infor¬ mation has been recorded, the viewing angle is calculated and stored in the control unit. This process generally takes a few minutes. In conditions of poor visibility, e.g. night, rain or winding roads, the calibration process may take up to 20 minutes. The calibration run does not have to be completed during the first drive following the start of the diagnostics job. It is reset with each power cycle and restarted again until it has been successfully completed. The system can be switched on and off during the calibration process. When the lane departure warning has been calibrated, the primed status display is shown when the lane departure warning is on.The conditions forthis are: • speed of over 70 km/h • lane markings detected. Following a replacement, e.g. of the control unit, the camera orthe windscreen, it is nec¬ essary to recalibrate the lane departure warning. The customer is notified by a Check Control message if the calibration process cannot be completed successfully after a net time of 7 minutes of straight-ahead travel at over 60 km/h. The system then makes an automatic attempt to carry out calibration again. If this attempt underthe conditions described above is unsuccessful, the system makes anoth¬ er attempt at calibration. A new Check Control message is only ever output after a power cycle following the first unsuccessful calibration attempt. 34 Lane Departure Warning This process repeats itself until calibration has been successfully completed. If the cali¬ bration run does not complete successfully, the vehicle must be brought into the after¬ sales service organization. In the after-sales service organization, the calibration process can be terminated manually using a diagnostics job. After the calibration process has been terminated, it must then be restarted once more. Diagnosis The control unit for the lane departure warning is compatible with diagnostics. The fault code memory can be read using the BMW diagnostic system. For test purposes, there is an option for controlling the vibration motor orthe camera, for example. You will find more detailed information in the BMW diagnostic system. Check Control Message Check control message Description Information in central information display Lane departure warning malfunction! Lane departure warning malfunction! Please visit the nearest BMW Service. u The Check Control messages are output by the lane departure warning orthe instrument cluster. If the control unit for the lane departure warning is faulty, it sends a request to have a Check Control message displayed. If the signal from the lane departure warning drops out, the instrument cluster generates a Check Control message. If a Check Control message is output, system availability is simply no longer displayed but the activation indication continues to be displayed in the instrument cluster or the head- up display, provided the system is activated. 35 Lane Departure Warning