Combined backup camera and driver alertness system for a vehicle

A combined backup camera and driver alertness system for a vehicle includes an imaging device that is adapted to be supported on a vehicle for capturing images adjacent a rearward portion of the vehicle. A sensor is provided that generates a signal when either (1) a transmission contained in the vehicle is operated in the rearward operating mode or (2) the vehicle is actually moved in the rearward direction. The system also includes a driver alertness processor and an image display. A data router routes the images from the imaging device to the driver alertness processor when not the signal is generated by the sensor and to the image display when the signal is generated by the sensor.

BACKGROUND OF THE INVENTION

This invention generally relates to camera-based obstacle avoidance systems for vehicles. In particular, this invention relates to an improved structure for a combined backup camera and driver alertness system for a vehicle.

When a vehicle is traveling in a reverse direction, the potential exists for collisions with both stationary and moving objects such as fire hydrants, guardrails, other vehicles, pedestrians, bicycle riders, children, animals, etc. To reduce the potential for collisions, some vehicles are provided with obstacle avoidance systems that use rearwardly viewing camera that provide the vehicle operator enhanced ability to view objects at the rear of the vehicle. These camera-based obstacle avoidance systems display images from the camera on a display, allowing a driver of the vehicle to more easily see objects that might otherwise be hidden from his or her view. These camera-based obstacle avoidance systems can also include an image processor that supplements the images from the camera by highlighting objects that are calculated to be in the path of the vehicle and/or suggesting directions for evasive movement. Some of these camera-based obstacle avoidance systems can also generate a warning signal to the driver, such as an audio signal, when it has been calculated that the vehicle may be about to collide with an object in its path of movement. Other camera-based obstacle avoidance systems are known to automatically implement collision avoidance measures, such as applying the vehicle brakes, when a collision with an object is imminent.

Driver fatigue is also a known causes of accidents, particularly when the vehicle is traveling in a forward direction. To address this, a variety of devices are known that generate a warning signal when certain characteristics of driver fatigue have been sensed or calculated. One of such characteristics is the relationship of the vehicle to lane markers on the road, referred to as road lane drift. Road lane drift typically refers to the gradual movement of the vehicle from a centered position on a road lane (as determined by the lane markers on the road) laterally toward such lane markers. Driver alertness systems traditionally use a forward aimed detection device, such as a camera or other sensor, to monitor the position of the vehicle relative to lane markers on the road. These driver alertness systems include algorithms that use the images from the camera (specifically, the locations of the lane markers that are illustrated in such images) to calculate the path of the vehicle relative to the lane markers. If the vehicle is drifting, weaving, or otherwise moving relative to the lane markers in a manner that suggests driver fatigue is occurring, the driver alertness system can generate an audio, optical, or tactile warning to the driver.

As mentioned above, driver alertness systems typically use a forwardly directed camera. Externally mounted camera and other road monitoring devices can be affected by weather conditions, such as wet roads, rain, snow, etc. that can partially obstruct the view of the lane markers on the road. Additionally, road hazards (such as stones and other debris) also can damage external monitoring devices. For these reasons, the cameras of many driver alertness systems are mounted in a passenger compartment of the vehicle, frequently adjacent to a rear view mirror provided on a front windshield. However, in this location, the camera is located relatively far from the surface of the road and, consequently, must “look” at the road from over the vehicle hood. Consequently, the camera is blocked from capturing images from the portion of the road that is immediately in front of the vehicle, and the lane markers that are visible to the camera are generally ten feet or often more in front of the vehicle. In addition, when the camera is located within the passenger compartment of the vehicle, the front windshield may distort the images that are captured thereby. Thus, it would be desirable to provide an improved structure for a combined backup camera and driver alertness system for a vehicle that avoids the issues mentioned above.

SUMMARY OF THE INVENTION

This invention relates to an improved structure for a combined backup camera and driver alertness system for a vehicle. The system includes an imaging device that is adapted to be supported on a vehicle for capturing images adjacent a rearward portion of the vehicle. A sensor is provided that generates a signal when either (1) a transmission contained in the vehicle is operated in the rearward operating mode or (2) the vehicle is actually moved in the rearward direction. The system also includes a driver alertness processor and an image display. A data router routes the images from the imaging device to the driver alertness processor when the signal is not generated by the sensor and to the image display when the signal is generated by the sensor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, there is illustrated inFIG. 1a vehicle10that includes a front portion12and a rear portion14. As is well known in the art, the vehicle10is designed to operate in either a forward direction16or a rearward direction18. An imaging device, such as a camera20, is supported on the rear portion14of the vehicle10, just above the license plate in the illustrated embodiment. Alternatively, as shown in phantom inFIG. 1, the camera20may be supported near on a trunk lid20′ or on a rear bumper20″. Preferably, the camera20is located close to a rearward most portion of the vehicle14′ so that the camera20does not have to be aimed over the trunk lid20′. This positioning also allows the camera20to capture areas immediately behind the vehicle10. The camera20is preferably provided with a wide angle or fish-eye lens that can cover a wide area over a short distance, which is suitable for use in both backup imaging and lane departure warning systems. The vehicle10includes a dashboard24having an instrument panel with a image display30for selectively displaying images generated from the camera20. As will be explained below, the image display30can assist a driver of the vehicle10to detect obstacles behind the vehicle10, especially those that below or off to the sides of the sight line of the rear view mirrors on the vehicle10.

As shown inFIG. 2, the vehicle10includes a transmission34that can be selectively operated in either a forward operating mode (wherein a forward gear ratio is selected for use such that the vehicle10can be moved in the forward direction16) and a rearward operating mode (wherein a reverse gear ratio is selected for use such that the vehicle10can be moved in the rearward direction18). A sensor36is responsive to the operating mode of the transmission34for generating a signal when the transmission34is operated in the rearward operating mode. To accomplish this, the sensor36may be mounted directly on the transmission34as shown or may be located remotely therefrom. Alternatively, the sensor36can be responsive to movement of a component within the transmission34so as to generate the signal when the vehicle10is actually moved in the rearward direction18. Other devices can be used to generate a signal when the vehicle10is actually moved in the rearward direction18. For example, the image generated by the camera20may be fed to a conventional image processor (not shown) that can calculate when the vehicle10is moving in the rearward direction18. Also, the position of a gear shift lever (not shown) of the transmission34can be used to determine when to generate the signal. Conversely, it is also possible to generate the signal by determining when the transmission34is operated in the forward operating mode or when the vehicle10is actually moved in the forward direction16.

The sensor36communicates over a wire38or other conventional data path (such as a wireless connection) with a data router40. Thus, the signal from the sensor36is fed to data router40when the transmission34is operated in the rearward operating mode or when the vehicle10is actually moved in the rearward direction18. The camera20also communicates over a wire42or other conventional data path (such as a wireless connection) with the data router40. Thus, the images from the camera20are also fed to the data router40whenever the camera20is operated.

The data router40is configured to selectively route the images from the camera20to either a rear image processor48or to a driver alertness processor50. When the data router40is receiving a signal from the sensor36(which, as discussed above, indicates that either the transmission34is operating in the rearward operating mode or that the vehicle10is actually moving in the rearward direction18), the data router40routes the images from the camera20to the rear image processor48over a wire44or other conventional data path (such as a wireless connection). Alternatively, when the data router40is not receiving a signal from the sensor36(which, as also discussed above, indicates that either the transmission34is operating in the forward operating mode or that the vehicle10is actually moving in the forward direction16), the data router40routes the images from the camera20to the driver alertness processor50over a wire46or other conventional data path (such as a wireless connection).

Thus, whenever the data router40is receiving the signal from the sensor36, the data router40routes the images from the camera20to the rear image processor48. The rear image processor48may, if desired, superimpose additional information on the images from the camera20in a known manner, then route the images from the camera20to the image display30through over a wire54or other conventional data path (such as a wireless connection). The rear image processor48may additionally analyze the images from the camera20to determine a collision with a object behind the vehicle10is imminent. If such a collision is determined to be imminent, the rear image processor48can send a signal over a wire56or other conventional data path (such as a wireless connection) to a rear obstacle alarm58.

On the other hand, whenever the data router40is not receiving the signal from the sensor36, the data router40routes the images from the camera20to the driver alertness processor50. The driver alertness processor50is configured to make a determination regarding driver fatigue or drowsiness. The images from the camera20may be provided from the data router40to the driver alertness processor50in a form of data other than images. The data represents vehicle positions relative to the road and, more specifically, relative to road edges, lane lines, and centerlines, as is known in the art. Algorithms are known in the art for determining or estimating the state of driver awareness, distraction, drowsiness, or fatigue using data relating to the vehicle lane inconsistency, such as weaving relative to road markers or indicating the vehicle is about to cross a road marker.

If a determination is made by the driver alertness processor50that a driver issue exists, such as fatigue, drowsiness or distraction, the driver alertness processor50sends a signal over a wire52or other conventional data path (such as a wireless connection) to an alarm60. The alarm60can be expressed in any desired form including, for example: an audio alarm in the form of the vehicle horn sounding or the radio volume increasing; a visual alarm in the form of a flashing light or display on the video imaging device20; and a tactile alarm in the form of a vibrating seat or steering wheel. One or more of these alarms may be generated simultaneously or sequentially, depending on the severity of the state of the driver as determined by the driver alertness processor50.

This invention has many advantages over previously used systems. Utilizing the rear viewing camera20for lane drift purposes provides improved data because a rear viewing camera20is usually mounted much lower than a typical passenger compartment-mounted front facing camera and may monitor road markers immediately behind the vehicle. Road monitoring systems are typically more accurate when the images from the camera20are taken in closer proximity of the vehicle. In addition, vehicle aerodynamics typically allow a more clear vision of the road behind the vehicle during precipitation in the form of rain, snow, or wet roads. A rear monitoring device also is less susceptible to damage from stones and road debris. It also is contemplated that the driver alertness processor50may be adapted to interpret vehicle fishtailing or other loss of control events that, at present, are determined using antiskid or similar systems. Rear facing monitoring devices may well be more suitable for this purpose.

This invention can easily be incorporated into vehicle designs using a rear view camera and direction sensor which may have been used in previous vehicle designs by the addition of a data router and forward direction alert system. The present invention similarly may be incorporated into existing vehicles having a rear view camera.

Referring toFIG. 3, in an alternate embodiment, the rear image processor48and the driver alertness processor50can be combined into a single microprocessor that is incorporated into the data router40. This combined processor could contain the software for both functions, as well as an input from the transmission direction sensor. It could perform the routing of the video data to the appropriate algorithm for rear obstacle detection or driver drowsiness detection, and also determine whether to send the processed video data to the image display30based on the transmission direction sensor input.