Abstract:
Devices, methods and systems are disclosed herein to describe a lane departure warning system that warns the driver that the vehicle is about to leave a current lane and enter an adjacent lane. The driver of the vehicle is identified, and a corresponding profile is accessed. The driver&#39;s pupils may be measured and compared to pupil size data stored in the accessed profile. If the difference in pupil size exceeds a certain threshold, then the vehicle may activate a passive lane departure detector that warns the driver each time the vehicle is getting too close to an adjacent lane, thus alerting the driver that the vehicle may be unintentionally drifting into the next lane. Additional driving tendencies, such as steering angles and braking force, may also be used to determine whether the driver may benefit from lane departure assistance and whether to trigger activation of the lane departure detector.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present invention describes methods, devices, and/or systems related to lane departure warning systems. For example, a lane departure warning system may warn a driver that the vehicle may be on the verge of leaving the current lane of a road and entering an adjacent lane of the road. 
         [0003]    2. Description of Related Art 
         [0004]    Various systems are being developed to prevent people from driving under the influence of alcohol. For example, some automobile manufacturers are currently exploring the possibility of integrating a breathalyzer test into the vehicle which a driver must pass in order to start the engine. However, such active deterrent systems may be further supplemented and/or replaced by other systems. 
       SUMMARY 
       [0005]    This Summary is included to introduce, in an abbreviated form, various topics to be elaborated upon below in the Detailed Description. This Summary is not intended to identify key or essential aspects of the claimed invention. This Summary is similarly not intended for use as an aid in determining the scope of the claims. 
         [0006]    Devices, systems, and methods discussed herein relate to a lane departure warning system that warns the driver when the vehicle is beginning to drift towards the lane markers (i.e., to guard against unintentionally drifting out of the current lane and into an adjacent lane). As used herein, intoxication or intoxicated, whether used in connection with impairment or not, is defined to include any type of impairment (e.g., resulting from alcohol, drugs, and/or other substances) and may further cover other situations where the driver is not legally impaired but assistance to the driver may be desirable nonetheless. For example, in an exercise of caution and to promote safety, intoxication of a driver may include situations where the driver is deemed by the system  200  to be impaired even if the driver is well below legally allowable thresholds. Moreover, the concepts described herein may further be applicable to determine if a driver&#39;s driving habits deviate too much from normal driving habits, thus suggesting, for example, that the driver is falling asleep, is extremely tired or fatigued, is a new driver, is a careless or reckless driver, is too distracted (e.g., talking on the phone or texting on the phone) or is otherwise not paying enough attention to operating the motor vehicle. 
         [0007]    In one embodiment, a lane departure warning system may determine if the driver may benefit from lane departure assistance (e.g., intoxicated, impaired, or distracted). If the driver is deemed to be in need of assistance, a lane departure detector (a subsystem of the lane departure warning system) may be activated to warn the driver each time the vehicle moves too close to the lane marker, as studies have shown that accidents may be reduced if the driver is warned before unintentionally entering into an adjacent lane. 
         [0008]    In one embodiment, the driver of the vehicle is identified, and a corresponding profile is accessed. The driver&#39;s pupils may be measured and compared to pupil size data stored in the accessed profile. If the difference in pupil size exceeds a certain threshold, then the vehicle may activate a passive lane departure detector that warns the driver each time the vehicle is getting too close to an adjacent lane, thus alerting the driver that the vehicle may be unintentionally drifting into the next lane. Additional driving tendencies, such as steering angles and braking force, may also be used to determine whether the driver may benefit from lane departure assistance and whether to trigger activation of the lane departure detector. 
         [0009]    In one embodiment, if the driver of the vehicle is not identified, the driver may be prompted to create a profile. For example, the driver may be requested to drive for a certain time period to allow the vehicle system to gather data on steering behavior, braking tendencies, and the like. In addition, the gathered data may include measuring one or both pupils of the driver&#39;s eyes. Even after the initial profile is complete, the system may update the profile by continuing to gather more data regarding the driver&#39;s driving patterns, which may improve the system&#39;s ability to more accurately respond to changes in the driver&#39;s normal operating tendencies. In one embodiment, the profile may be used to determine whether the driver may benefit from lane departure assistance. 
         [0010]    In one embodiment, the vehicle may receive data from a sensor or a camera directed to lane markers of a lane in which the vehicle is traveling. The data may be used to help determine whether the vehicle is starting to drift too close to the lane marker or is about to cross into an adjacent lane unintentionally. If the vehicle system ascertains that the vehicle is too close to the lane marker or is crossing the lane marker, a warning message may be outputted audibly and/or visually to the driver. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The features, obstacles, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, wherein: 
           [0012]      FIG. 1A  illustrates a vehicle with a pupil sensor or a camera according to one or more embodiments described herein; 
           [0013]      FIG. 1B  illustrates a vehicle on a multi-lane road with a lane-marker sensor and/or camera according to one or more embodiments described herein; 
           [0014]      FIG. 1C  illustrates a vehicle with both a pupil sensor and/or a camera and a lane-marker sensor and/or a camera according to one or more embodiments described herein; 
           [0015]      FIG. 2A  illustrates a block diagram of a vehicle system including a pupil sensor and/or a camera and a lane-marker sensor and/or a camera according to one or more embodiments described herein; 
           [0016]      FIG. 2B  illustrates a block diagram of a vehicle control unit according to one or more embodiments described herein; 
           [0017]      FIG. 3  illustrates a flow chart of a lane departure warning system according to one or more embodiments described herein; 
           [0018]      FIG. 4  illustrates a flow chart of a profile creation process related to a lane departure warning system according to one or more embodiments described herein; 
           [0019]      FIG. 5  illustrates a flow chart of an intoxication determination process as related to a lane departure warning system according to one or more embodiments described herein; 
           [0020]      FIG. 6  illustrates a flow chart of an operation of a lane departure detector as related to a lane departure warning system according to one or more embodiments described herein; and 
           [0021]      FIG. 7  illustrates a visual display and an audio warning as related to a lane departure warning system according to one or more embodiments described herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Apparatus, systems, and/or methods that implement the embodiments of the various features of the present invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate some embodiments of the present invention and not to limit the scope of the present invention. Throughout the drawings, reference numbers are re-used to indicate correspondence between referenced elements. 
         [0023]    Turning to  FIG. 1A , an interior  102  of a vehicle  100  is shown with a person in the driver&#39;s seat. In one embodiment, the vehicle interior  102  may include a steering wheel  105  with a camera  110  or other device configured to determine pupil size. Here, the camera  110  is shown mounted on the steering wheel  105  at a location such as the center. However, the camera  110  may be located anywhere that allows the camera  110  to obtain images of the driver&#39;s eyes, and more particularly, the pupils. For example, the camera  110  may be located on the instrument panel of the vehicle interior  102  (e.g., next to the fuel gauges), on the center control panel of the vehicle interior  102  (e.g., near radio/CD player controls), or on the frame or windshield of the vehicle interior  102 . While shown as a single camera, the camera  110  may include, in one embodiment, multiple cameras, wherein one or more cameras can focus on a respective eye of the driver. 
         [0024]    In one embodiment, four cameras may be used, with two cameras focused on each eye (not shown). Here, a first set of cameras may be located at one location (e.g., steering wheel) and a second set of cameras may be located at a second location (e.g., windshield). The first set of cameras may include at least two cameras, where a first camera is directed to the right eye of the driver and the second camera is directed to the left eye of the driver. Within the second set of cameras, a first camera may be directed to the right eye of the driver and a second camera may be directed to the left eye of the driver. By utilizing multiple cameras, a more accurate determination of the driver&#39;s pupil size may be obtained. 
         [0025]    Methods of detecting a person&#39;s eye and taking images of the eye using a camera (e.g., by using camera  110 ) are known and any of these methods may be used to obtain images of the driver&#39;s eye for measuring the diameter and/or size of the pupil. In one embodiment, the camera  110  may include a wireless transmitter which is configured to transmit image data to a vehicle&#39;s control unit via, for example, BLUETOOTH. In another embodiment, the camera  110  may send and receive data from the vehicle&#39;s control unit via a hard-wired cable line coupled to the vehicle&#39;s controller area network bus (CAN bus). 
         [0026]      FIG. 1B  illustrates the vehicle  100  on a road divided into multiple lanes. As an example, the road shown has four generally parallel lanes, including a left-most lane (defined by lane marker  140  and lane marker  135 ), a left-interior lane (defined by lane marker  135  and lane marker  130 ), a right-interior lane (defined by lane marker  130  and lane marker  125 ) and a right-most lane (defined by lane marker  125  and lane marker  145 ). However, the concepts herein are applicable to roads with any number of lanes. 
         [0027]    The vehicle  100  may include a lane sensor  115  located, for example, within the vehicle interior  102  (e.g., on the backside of a rear-view mirror  120 , between the mirror  120  and a windshield). In one embodiment, the lane sensor  115  may be placed on the exterior of the vehicle  100  (e.g., on the hood, grill or near the headlamps). The lane sensor  115 , in one embodiment, may be a camera that faces forward (e.g., the same direction that a driver would face when operating the vehicle) and capable of capturing images of the road, and in particular, the lane markers (e.g., lane markers  125 ,  130 ,  135 ,  140  and  145 ) of the road. The lane sensor  115  may detect the lane markers which define the lane in which the vehicle is traveling (e.g., lane markers  125  and  130 ) and calculate how close the vehicle  100  is to each of the two lane markers defining the road (e.g., lane markers  125  and  130 ). In one example, since the lane sensor  115  is at a fixed location, a distance between the lane sensor  115  and the lane markers of the road (e.g., lane markers  125  and  130 ) may be calculated from data obtained by the lane sensor  115 . 
         [0028]    In another example, the lane sensor  115  is a camera which obtains images of the lane markers (e.g., lane markers  125  and  130 ). Once the image or images are obtained, a distance between the lane markers (e.g., lane markers  125  and  130 ) and a point of reference (e.g., position of the lane sensor  115 ) may be calculated by processing the image or images based on, for example, the magnification of the lens, and/or the corresponding size of the other fixed elements captured in the image such as the hood of the vehicle. Image processing may be performed by a processor located within the camera, or performed by a remote image processor, for example, a processor coupled to the vehicle&#39;s CAN bus (e.g., processor  250  of  FIG. 2B , described below). By calculating the distance to the lane markers from a point of reference (e.g., the location of the lane sensor  115 ), the vehicle system may determine whether the vehicle  100  is near the center of the lane (and thus considered safely situated) or veering too close to one of the lane markers (e.g., as shown in  FIG. 1B , whether the vehicle  100  is moving too close to lane marker  125  or  130 ). 
         [0029]      FIG. 1C  illustrates a view of the vehicle interior  102  and the lane markers of the road (e.g., lane markers  125  and  130 ) through the windshield from the perspective of a driver or a passenger. In this embodiment, the placement of the camera  110  on the steering wheel  105  may be seen in relationship to the lane sensor  115  mounted on the rear view mirror  120 . In one embodiment, the camera  110  may be configured to re-position itself if needed, for example, in response to the driver adjusting the position of the steering wheel  105  or the seat. Similarly, the lane sensor  115  may be configured to re-position itself in response to the driver adjusting the position of the rear-view mirror  120 . For example, the camera  110  and/or the lane sensor  115  may be pivotably fixed in a housing which allows panning and tilting. In this manner, the camera  110  and the lane sensor  115  may re-position themselves to track the driver&#39;s eye and sense the lane markers of the road, respectively. 
         [0030]      FIG. 2A  is a block diagram illustrating a lane departure warning system  200 . As shown, the lane departure warning system  200  may include a CAN bus  205  supporting the data transfer between various vehicle components. For example, a camera  210 , a lane sensor  215 , a vehicle control unit  220 , an audio system control unit  225 , and a display control unit  230  may all be coupled to one another via the CAN bus  205 . However, other forms of coupling the devices may be used. For example, the camera  210  and the lane sensor  215  may include first and second BLUETOOTH transceivers, respectively, both of which may be in communication with a third BLUETOOTH transceiver coupled to the CAN bus  205 . 
         [0031]      FIG. 2B  is a block diagram of a vehicle control unit (e.g., vehicle control unit  220 ). The vehicle control unit  220  may receive images of a pupil and/or related data (e.g., pupil size) from the camera  210  and may further receive images of the lane markers and/or related data (e.g., distance between the vehicle  100  and a lane marker, for example, lane markers  125 - 145 ) from the lane sensor  215 . The vehicle control unit  220  may include a processor  250 , a memory  255  (e.g., a physical memory such as a hard drive, EEPROM, FLASH, CD-ROM, RAM, DVD, and the like), a pupil comparison module  260 , a pupil size measurement module  265 , a lane departure determination module  270 , a steering data comparison module  275 , a braking data comparison module  280  and a transceiver  285 . While discussed as separate structural elements in one embodiment, one skilled in the art will understand that the components of the vehicle control unit  220  may be combined and/or integrated into fewer components, and/or separated such that some of these components are located in a separate device (e.g., at the camera  210  or the lane sensor  215 ). The function of these structural components will be discussed below in connection with  FIGS. 3-5 . 
         [0032]    Turning to  FIG. 3 , a flow chart of an operation of a lane departure warning system (e.g., lane departure warning system  200 , hereafter referred to as “the system  200 ”) is illustrated. In one embodiment, the system  200  may comprise any and all components described in  FIGS. 2A and 2B , among other components. At step  305 , the driver may be identified by the system  200 . One or more identification methods and systems known in the art may be employed to determine the identity of a driver, such as an identity of the key or a key fob, a biometric sensor, retinal recognition, or other method (e.g., prompting the driver to input a password or select options among a menu of driver names and IDs displayed at the start-up of the vehicle). Once the driver is identified as a known driver, the system  200  may determine whether a completed profile exists for the driver at step  310 . 
         [0033]    If a completed profile is not available for the driver as determined at step  310 , the process moves to step  315  where a distinction between an incomplete profile and a non-existent profile is made by the processor (e.g., the processor  250 ). If the processor (e.g., the processor  250 ) determines that the profile is incomplete, the existing profile data is retrieved in step  320 . At step  325 , the data still needed to complete the profile is determined by the system  200  (e.g., by the processor  250  of the system  200 ) and as the driver operates the vehicle, the needed data is collected and stored at step  330 . At step  335 , if the profile is determined to be complete, the system  200  may, in one embodiment, cease to collect information or data for the profile and may begin to obtain data to determine whether the driver may benefit from lane departure assistance (e.g., as shown in  FIG. 3  by moving the process along to step  370 ). 
         [0034]    For situations where a profile does not exist as determined by step  315 , the system  200  may invite the driver to create a profile at step  340 . If the driver accepts the invitation at step  345 , the profile creation process begins at step  350 , which is more fully described in  FIG. 4 . However, if the driver declines the invitation at step  345 , the profile creation process may be skipped at step  355 , and the lane departure detector remains in a deactivated state. In one embodiment, the lane departure detector may be a subsystem of the lane departure warning system  200  and may include, but is not limited to, the processor  250 , the memory  255 , the lane sensor  215 , the audio system control unit  225 , the display control unit  230 , and the lane departure determination module  270 . 
         [0035]    Referring back to step  310 , if a completed profile exists for the driver, then at step  360 , the system  200  may retrieve the driver&#39;s profile data from, for example, the memory  225 . The profile data may include, among other information, pupil size, average braking force data, steering angle data, and the like. As the vehicle  100  is being operated, current data such as the pupil size of the driver, the average braking force data, or the steering angle data, is collected at step  365 . For example, to collect the pupil size of the driver, a camera (e.g., camera  210 ) may detect and take photos of the driver&#39;s eyes and send the image data to the vehicle control unit (e.g., vehicle control unit  220 ) where the image may be processed to determine the pupil size. In one embodiment, a pupil measuring apparatus (e.g., pupil size measurement module  265 ) may measure and/or calculate the diameter of a driver&#39;s pupil from an image of the eye obtained from the camera (e.g., camera  210 ). At step  370 , the measured or calculated pupil diameter and the pupil diameter saved in the profile may be transmitted to a diameter comparing module (e.g., pupil size comparison module  260 ) for comparison. At step  375 , if the pupil size comparison module  260  determines that a difference in the diameter sizes exceeds a certain threshold, the lane departure detector may be activated at step  380 . For example, when the measured or calculated pupil diameter deviates more than 5%, preferably, from the pupil diameter saved in the profile, a processor (e.g., processor  250 ) may activate the lane departure detector, as the driver is deemed to be impaired or intoxicated and thus, may benefit from the lane departure warnings. While this example uses a 5% deviation, other deviations levels may be implemented, such as 6%, 6.5%, or any value between 0-50%. However, if the system  200  determines that the threshold has not been exceeded in step  375 , the process may return to step  365  and the size of the driver&#39;s pupil(s) may be collected and analyzed again. 
         [0036]    Continuing to analyze the driver&#39;s pupil may guard against the scenario where the driver consumes a large amount of alcohol shortly prior to operation of the vehicle  100  such that his or her pupils have not yet fully dilated or otherwise changed in size at the moment the vehicle  100  initially processes the size of the pupil. By repeating the collection and analysis processes, the system  200  is able to take into account any further change in the size of the pupil due to the absorption of alcohol or drugs thereby achieving a more accurate assessment of whether the driver is intoxicated. 
         [0037]    For simplicity, steps  365  and  370  have been described with respect to pupil differences. However, in one embodiment, as further described in  FIG. 5 , even if the pupil size comparison fails to suggest that the driver is intoxicated, other driving data may be used to infer that the driver is impaired and may benefit from lane departure warnings when the collected data (e.g., steering angles and braking forces) indicate driving patterns outside the norm. 
         [0038]    In one embodiment, and in an exercise of caution, once the driver is determined to be legally intoxicated (e.g., the threshold is determined to have been exceeded in step  375 ), the driver may be deemed intoxicated for the remainder of the driving session (e.g., until the driver shuts off the engine) even if at some point during the driving session the driver recovers from an intoxicated state and returns to a non-intoxicated state. 
         [0039]    In one embodiment, the lane departure detector may be deactivated after the system  200  determines that the driver is no longer intoxicated (i.e., by continuously monitoring pupil sizes and if the pupil size returns to a size below the threshold, de-activating the lane departure detector). 
         [0040]    In one embodiment, when the driver is above legally allowable thresholds of intoxication, the vehicle  100  may be shut down. For example, the driver may be warned that the engine of vehicle  100  is going to be shut down, and the driver may be given a short amount of time, such as thirty seconds, to move the vehicle  100  over to the shoulder of the road or a parking space. In one embodiment, the vehicle  100  may decrease five mph in speed every thirty seconds to promote a safe driving experience. Contemporaneously, the emergency lights of the vehicle may be activated to alert other drivers on the road. Such an embodiment may be used in conjunction with the other concepts described herein. 
         [0041]      FIG. 4  illustrates a flow chart depicting one embodiment of a profile creation process. At step  405 , a driver identification is created. The driver identification may be created based on the input of an alphanumeric pass code or via a biometric reading (e.g., fingerprint or voice-print). At step  410 , the driver&#39;s pupil may be measured and stored as a baseline pupil size. The diameter of the pupil of the driver&#39;s right or left eye, or the diameters corresponding to both pupils of the driver&#39;s eyes may be measured. At step  415 , statistical data of the driver&#39;s driving tendencies may be collected as the driver operates the vehicle  100 . For example, the processor  250  may measure the speed of the vehicle  100  and steering force applied as the vehicle  100  makes turns. The processor  250  may store in the memory  255  data related to how “hard” or “soft” the driver typically makes turns on the road. For example, some drivers may slow the vehicle  100  to almost a complete stop before making a turn, while other drivers may aggressively steer the vehicle  100  when approaching a turn which may result in sharper turns. Such data may be taken over a span of tens or hundreds of miles to establish the tendencies of a driver. 
         [0042]    In another example, braking force may be measured each time the vehicle  100  decelerates. Obtaining samples of braking force applied yields a more comprehensive picture of how the driver typically utilizes the brakes in operating the vehicle  100 . Certain drivers may ease into the brakes and slow the vehicle  100  over a longer period of time and/or distance, while other drivers may consistently wait and slam on the brakes closer to when braking of the vehicle  100  is absolutely needed to prevent an accident. These tendencies may be determined by collecting samples over a substantial period of driving time and may be used, in one embodiment, to assist in ascertaining whether the driver is impaired. 
         [0043]    Other examples of driving data collected may include the time of day the vehicle  100  is being operated by the driver, the average speed of the vehicle  100 , and the like. More particularly, the time of day the vehicle  100  is being operated may be correlated with other data collected such as braking force applied and steering angle data to assist in determining whether the driver is impaired. For example, if a driver tends to drive more carefully (e.g., longer braking spans, lower vehicle speeds, etc.) late at night compared to the daytime, such factors may be taken into account when determining whether the driver is impaired. 
         [0044]    Referring back to  FIG. 4 , once sufficient data is obtained by the system  200  at step  420 , the profile creation process is completed and the profile is marked as such at step  425 . By completing the profile, the next time the driver operates the vehicle  100 , the system  200  may collect impairment indication data (e.g., in one embodiment, the same data collected to establish the profile) and compare the impairment indication data to the profile data to determine whether the driver is intoxicated. 
         [0045]      FIG. 5  illustrates one example of determining whether the driver is impaired by using the collected impairment indication data. At step  505 , the currently measured pupil size may be compared with the pupil size data stored in the memory  225 . In one example, the pupil size data collected and compared may be of one eye or both eyes. At step  510 , the system  200  determines if the difference between the pupil size of the currently measured pupil and the stored pupil data exceeds 5%. In one embodiment, where both pupils of the driver is measured, each pupil may need to be 5% longer or shorter than the respectively stored pupil sizes before the process moves to step  540 . If the pupil size fails to exceed the threshold as determined in step  510 , the process moves to step  515 , where the braking force (e.g., average braking force of the current driving session) is compared to the stored braking force data (e.g., average braking force recorded in the profile data). In one example, the braking data comparison module  280  may receive data from the memory  225  regarding the average braking force stored for the profile and may receive data from the processor  250  regarding the average braking force of the current driving session. The braking data comparison module  280  may compare the two average values to determine whether a greater than 5% difference exists between the two values at step  520 . If so, the process may move to step  525  where the current steering angle data (e.g., average steering angle for turns and/or curves of the current driving session) is compared to the stored steering data (e.g., average steering angle for turns and/or curves recorded in the profile data). In one example, the steering data comparison module  275  may receive data from memory  255  regarding the average steering angle stored for the profile and may receive data from the processor  250  regarding the steering angle of the current driving session. The steering data comparison module  275  may then compare the two average values to determine whether a greater than 5% difference exists between the two values at step  530 . If the result is affirmative, the lane departure detector may be activated at step  540 ; otherwise the lane departure detector remains deactivated. 
         [0046]    Once the lane departure detector is activated, the driver may be warned each time the vehicle veers too close to the lane markers of the current lane in which the vehicle is traveling.  FIG. 6  is a flow chart of the operation of the lane departure detector. As discussed above, in one embodiment, the lane departure detector may be a subsystem of the lane departure warning system  200 . One skilled in the art will appreciate that other processors, memories, and the like may be further included and/or dedicated to performing certain steps of the lane departure detector. 
         [0047]    At step  605 , the lane departure detector determines the current lane that the vehicle is traveling in, for example, by using lane sensors (e.g., lane sensor  215 ) to ascertain the lane markers to the left and the right of the vehicle  100 , respectively. Once the lane markers are determined, the lane departure determination module  270  may calculate a distance between the tire of the vehicle  100  closest to the lane marker and the lane marker itself. At step  610 , the lane departure determination module  270  may ascertain whether the vehicle  100  is encroaching on the edge of the lane based on the calculated distance alone or in combination with other factors. Other factors that may be taken into account include, for example, whether the vehicle  100  is turning on a curved portion of a road (e.g., the lane departure determination module  270  may allow the vehicle  100  to encroach closer to the edge of the lane before triggering a warning than if the vehicle  100  were on a straight portion of the lane), the speed of the vehicle  100  (e.g., at lower speeds, the lane departure determination module  270  may allow the vehicle  100  to encroach closer to the edge of the lane before triggering a warning), the width of the lane (e.g., with a narrower lane, the lane departure determination module  270  may allow the vehicle  100  to encroach closer to the edge of the lane before triggering a warning), time of day (daytime vs. night time), weather (e.g., cold, icy conditions as opposed to a clear, sunny day), among other factors. The lane departure determination module  270  may continue to monitor whether the vehicle  100  is too close to either one of the two closest lane markers (e.g., lane markers  125  and  130  of  FIG. 1B ). Once the lane departure determination module (e.g., a lane departure determination module  270 ) determines that the vehicle  100  is encroaching too closely to the lane marker (e.g., lane markers  125  and  130  of  FIG. 1B ) at step  610 , a warning may be issued to the driver through the audio and/or display systems (e.g., audio and display system  225  and  230 ) of the vehicle  100  at step  615 . Typically for non-intoxicated drivers, a warning system may warn the driver when the vehicle  100  actually crosses the lane marker (e.g., lane markers  125  and  130  of  FIG. 1B ) as to avoid overly annoying the driver each time the driver moves too close to the lane markers (e.g., lane markers  125  and  130  of  FIG. 1B ). 
         [0048]      FIG. 7  illustrates an example of a visual and/or audio warning. The center console  700  for a vehicle  100  may include a display  705  and speakers  720 . The warning message  710  may be displayed, and the same warning message  715  may be audibly played either simultaneously or contemporaneous to each other. The displayed warning message  710  may flash, change colors, use large fonts, and/or otherwise convey the warning  710  to the driver in an effective manner. Alternatively, the driver may configure the system to issue warnings (e.g., warning  710  or  715 ) via only one of the two outputs (e.g., the speakers  720  or the display  710 ). 
         [0049]    With respect to the audible warning  715  issued through the speakers  720 , other examples of warning sounds may include, for example, a noise normally heard when a vehicle drives over a rumble strip (e.g., a periodic “rumble” sound). In one embodiment, the speaker closest to the lane marker encroached may be utilized to output the sound to provide the driver a directional sound so the driver may easily ascertain which lane marker the vehicle  100  is encroaching (not shown). In one embodiment, the warning message or sound (e.g., warning  710  or  715 ) may have priority over any audible message currently being played through the speaker  720  (e.g., songs on the radio or from the CD player, navigation commands from a GPS, and the like). Furthermore, the decibel level for the message may be preset such that even if the current decibel output level of the speaker  720  is higher or lower than the preset level for the message, the speaker  720  may automatically adjust to the preset decibel level for the message for outputting of the message, before returning to the previous decibel level. 
         [0050]    Turning back to  FIG. 6 , after the warning (e.g., warning  710  or  715 ) is issued in step  615 , if the vehicle  100  responds to the warning (e.g., warning  710  or  715 ) at step  620  (e.g., by moving back towards the center of the lane), the warning (e.g., warning  710  or  715 ) may be stopped in step  625 . However, if the vehicle  100  fails to respond to the warning (e.g., warning  710  or  715 ), at step  630 , the lane departure determination module  270  may determine whether the vehicle  100  is within new lane markers. If not, the warning (e.g., warning  710  or  715 ) may continue to be outputted. However, if the vehicle  100  is determined to be in a new lane, the process reverts back to step  605 . 
         [0051]    In one embodiment, the processor  250  may, before step  615 , perform an additional step of checking the activation of the turn signal before issuing the warning (e.g., warning  710  or  715 ). If the turn signal is activated, the warning (e.g., warning  710  or  715 ) might not be given since it is likely that the driver actually intends to exit the current lane and hence, the vehicle  100  would necessarily encroach and cross over the lane marker. 
         [0052]    Those of ordinary skill would appreciate that the various illustrative logical blocks, modules, and algorithm steps described in connection with the examples disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. Furthermore, the present invention can also be embodied on a machine readable medium causing a processor or computer to perform or execute certain functions. 
         [0053]    To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosed apparatus and methods. 
         [0054]    The various illustrative logical blocks, units, modules, and circuits described in connection with the examples disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. 
         [0055]    The steps of a method or algorithm described in connection with the examples disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The steps of the method or algorithm may also be performed in an alternate order from those provided in the examples. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an Application Specific Integrated Circuit (ASIC). The ASIC may reside in a wireless modem. In the alternative, the processor and the storage medium may reside as discrete components in the wireless modem. 
         [0056]    The previous description of the disclosed examples is provided to enable any person of ordinary skill in the art to make or use the disclosed methods and apparatus. Various modifications to these examples will be readily apparent to those skilled in the art, and the principles defined herein may be applied to other examples without departing from the spirit or scope of the disclosed method and apparatus. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.