Patent Publication Number: US-2017358211-A1

Title: Warning system for an automated vehicle

Description:
TECHNICAL FIELD OF INVENTION 
     This disclosure generally relates to a warning system for an automated vehicle, and more particularly relates to a system that transmits a proximity-warning to a target-vehicle when a separation-distance between a host-vehicle and the target-vehicle is less than a distance-threshold, where the proximity-warning includes the GPS-coordinates of the target-vehicle and the separation-distance. 
     BACKGROUND OF INVENTION 
     It is known to equip vehicles with sensors to detect the proximity of other-vehicles, and issue a warning to an operator when any of the other-vehicles are too close. However, an undetected failure of a sensor and/or severe weather conditions and/or an unexpected traffic-scenario may lead to the warning not being issued. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment, a warning system for an automated vehicle is provided. The system includes an object-detector, a location-detector, a transceiver, and a controller. The object-detector is used to determine a separation-distance to a target-vehicle from a host-vehicle. The location-detector is used to provide global-positioning-system-coordinates (GPS-coordinates) of the target-vehicle. The transceiver is used to transmit a proximity-warning to the target-vehicle. The controller is in communication with the object-detector, the location-detector, and the transceiver. The controller is configured to operate the transceiver to transmit the proximity-warning when the separation-distance between the host-vehicle and the target-vehicle is less than a distance-threshold. The proximity-warning includes the GPS-coordinates of the target-vehicle and the separation-distance. 
     Further features and advantages will appear more clearly on a reading of the following detailed description of the preferred embodiment, which is given by way of non-limiting example only and with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will now be described, by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  is diagram of a warning system in accordance with one embodiment; and 
         FIG. 2  is a traffic-scenario encountered by the system of  FIG. 1  in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a non-limiting example of a warning system  10 , hereafter referred to as the system  10 , which is generally configured for use by an automated vehicle, for example a host-vehicle  12 . The examples presented herein are generally directed to instances when the host-vehicle  12  is being operated in an automated-mode  14 , i.e. a fully autonomous mode, where a human operator (not shown) of the host-vehicle  12  does little more than designate a destination to operate the host-vehicle  12 . However, it is contemplated that the teachings presented can be applied to instances when the host-vehicle  12  is operated in a manual-mode  16  where the degree or level of automation may be little more than providing steering advice to the human operator who is generally in control of the steering, accelerator, and brakes of the host-vehicle  12 , i.e. the system  10  merely assists the human operator on an as-needed basis to reach the destination and/or avoid a collision. 
     The system  10  includes an object-detector  18  used to determine a separation-distance  20  to a target-vehicle  22  from a host-vehicle  12 . As will be explained in more detail below, the system  10  is generally configured to take some sort of action if the target-vehicle  22  gets too close to the host-vehicle  12 , hence the need for the object-detector  18  to determine the separation distance  20 , and optionally determine a direction  32  from the host-vehicle  12  to the target-vehicle  22 . That is, the object-detector  18  may also be used to determine a direction  32  to the target-vehicle  22  from the host-vehicle  12  in addition to being used to determine the separation-distance  20 . The usefulness of the separation-distance  20  and the direction  32  will be explained later in this disclosure. It is also contemplated that the system  10  can be used when the host-vehicle is operated in the manual-mode  16 , where the host-vehicle  12  still senses the separation-distance  20 . 
     The function of the object-detector  18  may be provided by a camera  24 , a radar-unit  26 , a lidar-unit  28 , an ultrasonic transducer (not shown), or any combination thereof. The function of the object-detector  18  may also be provided by or supplemented by a transceiver  30  configured for vehicle-to-infrastructure (V2I) communications, vehicle-to-vehicle (V2V) communications, and/or vehicle-to-pedestrian (V2P) communications, which may be generically referred to as V2X communications, as will be recognized by those in the art. 
     The system  10  includes a location-detector  34  used to provide global-positioning-system-coordinates, hereafter referred to as the GPS-coordinates  36 , of the target-vehicle  22 . In one embodiment envisioned, the location-detector  34  may include a location-device  38 , such as GPS-receiver, which is mounted on the host-vehicle  12  and used to determine the host-coordinates  40  (i.e. GPS coordinates) of the host-vehicle  12 . The host-coordinates  40  can be used to determine a location on a digital-map  42 , the usefulness of which will be explained later, and/or can be used to determine the GPS-coordinates  36  of the target-vehicle  22  by offsetting the host-coordinates  40  in accordance with the separation-distance  20  and the direction  32 . Alternatively, the target-vehicle  22  may be equipped with a GPS-receiver and may broadcast the GPS-coordinates  36  of the target-vehicle  22  using, for example, V2V communications. As another alternative, the GPS-coordinates  36  may be determined and provided by traffic-monitoring equipment via V2I communications. Furthermore, it is contemplated that an imaging-device such as the camera  24 , the radar-unit  26 , and/or the lidar-unit  28  could be used to determine the host-coordinates  40  of the host-vehicle  12  and/or the GPS-coordinates  36  of the target-vehicle based on navigation-feature matching to the digital-map  42 . 
     As noted above, the system  10  includes the transceiver  30  which is used by the system  10  to transmit a proximity-warning  44  to the target-vehicle  22 , but the transceiver  30  is not limited to only this use. That is, the transceiver  30  may be used to transmit other-messages to recipients other than the target-vehicle  22 . The transceiver  30  may transmit and receive messages using radio-frequency (RF) signals in accordance with known V2X protocols. Alternatively, the transceiver  30  may use infrared (IR) light to transmit the proximity-warning  44  as the distance that the proximity-warning  44  must travel is expected to be rather short, e.g. less than twenty-five meters (25 m). 
     The system  10  includes a controller  46  in communication with the object-detector  18 , the location-detector  34 , and the transceiver  30 . The communication may be by way of wires, wireless communication, or optical-fiber, as will be recognized by those in the art. The controller  46  may include a processor (not specifically shown) such as a microprocessor or other control circuitry such as analog and/or digital control circuitry including an application specific integrated circuit (ASIC) for processing data as should be evident to those in the art. The controller  46  may include memory (not specifically shown), including non-volatile memory, such as electrically erasable programmable read-only memory (EEPROM) for storing one or more routines, thresholds, and captured data. The one or more routines may be executed by the processor to perform steps for determining, for example, if a present-vector  48  of the target-vehicle  22  suggests that some action by the host-vehicle  12  and/or the other-vehicle  50  ( FIG. 2 ) is necessary to avoid a collision based on signals received by the controller  46  from the object-detector  18  as described herein. 
     In particular, the controller  46  is configured to operate the transceiver  30  to transmit the proximity-warning  44  when the separation-distance  20  between the host-vehicle  12  and the target-vehicle  22  is less than a distance-threshold  52 , one meter (1 m) for example. Advantageously, the proximity-warning  44  communicates or includes the GPS-coordinates  36  of the target-vehicle  22 , and the separation-distance  20 , as including the GPS-coordinates  36  in the message (the proximity-warning  44 ) will help to notify the target-vehicle  22  that corrective action by the target-vehicle  22  is necessary to avoid a possible collision. That is, the target-vehicle  22  will be able to determine that the proximity-warning  44  is directed at the target-vehicle  22 . A further advantage of including the GPS-coordinates  36  of the target-vehicle  22  in the proximity-warning  44  is that the other-vehicle  50  and/or any other vehicles not shown in  FIG. 2  but close enough to benefit from being notified that the target-vehicle  22  is too close to the host-vehicle  12 . The advantage may be that the other-vehicle  50  and/or any other vehicles not shown in  FIG. 2  may take some preemptive action in case a collision between the target-vehicle  22  and the host-vehicle  12  do collide, and/or make room for the host-vehicle  12  to take some evasive action if the target-vehicle fails to respond accordingly to the proximity-warning  44 . 
     It is also contemplated that the proximity-warning  44  may include the direction  32  and/or the host-coordinates  40  as this may help the target-vehicle  22  and/or any other vehicles determine who (i.e. which vehicle) is transmitting the proximity-warning  44 . For example, the direction  32  may give the target-vehicle  22  an instant indication of which direction the target-vehicle  22  should steer to avoid being too close to another vehicle (i.e. the host-vehicle  12 ). Making quick use of the instant indication may be preferable rather than use the sensors of the target-vehicle  22  to determine why the proximity-warning  44  has been issued as there is some evidence that those sensors are not performing adequately. 
       FIG. 2  illustrates a non-limiting example of a traffic-scenario  54  where the present-vector  48  of the target-vehicle  22  indicates that the target-vehicle  22  is drifting toward or changing lanes into the host-vehicle  12 . While the illustration suggests that the separation-distance  20  is determined or measured in a lateral-direction, it is contemplated that the separation-distance  20  may alternatively be measured in a longitudinal-direction, or some direction therebetween, i.e. a diagonal-direction. If the separation-distance  20  becomes less than the distance-threshold  52  ( FIG. 1 ), the proximity-warning  44  is transmitted by the host-vehicle  12  to warn the target-vehicle  22  about the situation. The expectation is that the target-vehicle  22  will respond by changing the present-vector  48  of the target-vehicle  22  to steer away from the host-vehicle  12 . However, if the target-vehicle  22  continues to travel towards the host-vehicle  12 , the host-vehicle  12  may need to take some additional action. 
     The controller  46  may also be in communication with vehicle-controls  56  of the host-vehicle  12 . By way of example and not limitation, the controller  46  may be configured to operate the host-vehicle  12  to increase  60  the separation-distance  20  after proximity-warning  44  is transmitted and the separation-distance  20  is less than a danger-threshold  58 , one-half-meter (0.5 m) for example, and noting that the danger-threshold  58  is less than the distance-threshold  52 . That is, the system  10 , or more specifically the controller  46 , may take evasive action, possibly taking control away from a human-operator (not shown) of the host-vehicle  12 , only after the danger-threshold  58  is violated, where the danger-threshold  58  is closer that the distance-threshold  52  which causes transmission of the proximity-warning  44 . For the traffic-scenario  54 , the evasive action may include, but is not limited to, braking and/or steering the host-vehicle  12  closer to the other-vehicle  50 . It is contemplated that steering the host-vehicle  12  closer to the other-vehicle  50  may cause the other-vehicle  50  to transmit another proximity-warning (not shown) and/or steer the other-vehicle  50  away from the host-vehicle  12 . 
     It is contemplated that the controller  46  may be programmed with predetermined values for the distance-threshold  52  and/or the danger-threshold. However, it is recognized that these values may need to be adjusted depending on a variety of factors such as speed, traffic-density, weather-conditions, etc. By way of example and not limitation, the controller  46  may be further configured to determine a lane-center-confidence  62  of the host-vehicle, and determine the distance-threshold  52  and/or the danger-threshold  58  based on the lane-center-confidence  62 . For example, if the lane-markings  64  ( FIG. 2 ) have been consistently detected for a relatively long period of time, more than eight seconds (8 s) for example, and the host-vehicle  12  is centered between the lane-markings  64 , then the lane-center-confidence is relatively high and there should be less need for the host-vehicle  12  to take evasive action. As such, if the lane-center-confidence is high, the exemplary value for the danger-threshold  58  of 0.5 m is likely acceptable. However, if the if the lane-center-confidence is relatively low because the lane-markings  64  ( FIG. 2 ) have not been consistently detected and/or have been detected for a relatively short period of time, less than three seconds (3 s) for example, the value of the danger-threshold  58  may be justifiably increased so the host-vehicle  12  considers making an evasive maneuver sooner when the target-vehicle  22  and the host-vehicle  12  approach each other. 
     Accordingly, a warning system (the system  10 ), a controller  46  for the system  10 , and a method of operating the system  10  is provided. The system  10  is generally configured so that when the cause of the target-vehicle  22  being too close to the host-vehicle  12  is apparently the fault of the target-vehicle  22 , a proximity-warning  44  is transmitted to warn the target-vehicle  22  (or the operator of the target-vehicle  22 ) to move away from the host-vehicle  12 . If transmitting the proximity-warning  44  is not effective to have the target-vehicle  22  change course, then the host-vehicle  12  may take evasive action as a last resort. 
     While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.