Abstract:
A pedestrian protection system from a vehicle utilizes GPS data to reduce the number of false positive detections for impacting an object determined to be a pedestrian. The GPS data is used to focus on area of increased and/or decreased pedestrian presence to alter a reaction threshold for the vehicle. Additionally, the GPS data can be used for more accurate analysis of the likelihood of an impact.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to automotive vehicles, and more particularly to safety systems for automotive vehicles. 
       BACKGROUND 
       [0002]    An automotive vehicle may include a pedestrian protection system to warn the vehicle operator and adapt the vehicle responses to avoid impact and to minimize pedestrian injuries. The pedestrian protection system utilizes sensors and cameras to detect objects in the vehicle path. The pedestrian protection system analyzes the data to determine if the detected objects are pedestrians and warns the vehicle operator of a likely pedestrian impact. By alerting the vehicle operator of an upcoming pedestrian impact the vehicle operator may take action to avoid the pedestrian. 
         [0003]    The pedestrian protection system may further initiate vehicle actions to avoid impact with a pedestrian or at least to mitigate the injuries to the pedestrian. The pedestrian protection system may even take autonomous action to avoid impact and/or mitigate injuries, such as application of the vehicle brakes. 
         [0004]    However, the known pedestrian protection systems may sometimes provide a false pedestrian detection. Thus the vehicle may react to a false detection and unnecessarily alter the vehicle behavior. Limiting false detection by the system would improve system performance and limit unnecessary reactions by the vehicle that may be unwanted by the driver. 
         [0005]    The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
       SUMMARY 
       [0006]    A method of controlling a vehicle to increase pedestrian protection comprises monitoring data from a plurality of sensors with an electronic control unit. The ECU determines a confidence factor that a detected object proximate to the vehicle is a pedestrian and analyzes GPS data to determine if the vehicle is in one of an area of increased pedestrian presence, decreased pedestrian presence and indeterminate pedestrian presence. A reaction threshold is selected based upon the analysis of the GPS data and the confidence factor is compared to the reaction threshold. 
         [0007]    Another method of controlling a vehicle to increase pedestrian protection comprises monitoring data from a plurality of sensors with an ECU and determining a confidence factor that a detected object proximate to the vehicle is a pedestrian. The confidence factor is compared to a reaction threshold. The ECU also determines if an impact with the detected object is likely to occur and compares GPS data to the object position and the vehicle position to alter the likelihood that an impact will occur. 
         [0008]    A pedestrian protection system for a vehicle comprises a plurality of sensors to monitor an area proximate to the vehicle and an ECU connected to the plurality of sensors to determine if an object detected by the sensors is a pedestrian. The ECU is configured with instructions for determining a confidence factor that a detected object proximate to the vehicle is a pedestrian, analyzing GPS data to determine if the vehicle is in one of an area of increased pedestrian presence, decreased pedestrian presence and indeterminate pedestrian presence selecting a reaction threshold based upon the analysis of the GPS data and comparing the confidence factor to the reaction threshold. 
         [0009]    Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0011]      FIG. 1  is a schematic side view of a vehicle having a pedestrian protection system of the present invention; 
           [0012]      FIG. 2  is a schematic diagram of an exemplary implementation of the pedestrian protection system for the vehicle of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements.  FIG. 1  is a schematic illustration of a vehicle  10  having a pedestrian protection system  12 . The pedestrian protection system  12  preferably incorporates other existing vehicle  10  systems such as a forward collision alert system  14 A or a back-up assist system  14 B for the vehicle  10  and may be utilize the same sensors and components, as described below. Throughout the applications the relative directions of forward and rear are in reference to the direction which an operator for the vehicle  10  would primarily be facing when operating the vehicle  10 . 
         [0014]    The pedestrian protection system  12  may be connected to other systems for the vehicle  10  including the forward collision alert system  14 A, a back-up assist system  14 B, a supplement restraint system  14 C, a driver warning  14 D, a brake system  16 , and a steering system  18 . Other systems, not shown, that provide information that may be utilized by the pedestrian protection system  12  may also be connected. Likewise, other systems, not shown, that may be used to control the vehicle  10  may also be connected to receive signals from the pedestrian protection system  12 . 
         [0015]    The pedestrian protection system  12  includes a plurality of sensors  20 . The sensor(s)  20  may be any of a proximity, lidar, camera, etc. The pedestrian protection system  12  includes a module having an electronic control unit (ECU)  24 . The ECU  24  receives input from the various vehicle systems  14 A- 14 D,  16 ,  18  and sensors  20 . As mentioned above, the sensors  20  providing input data to the ECU  24  may also be part of already existing systems  14 A- 14 D,  16 ,  18  in the vehicle  10 . The ECU  24  monitors the vehicle  10  information which includes monitoring a GPS system  26  and may include other systems and sensors such as, weather sensors, wheel speed sensors, a speedometer, a accelerometer, a steering sensor and a brake sensor. One skilled in the art would be able to determine which other sensors and systems may provide useful information to the pedestrian protection system  12 . 
         [0016]    The sensors  20  detect an object  28 . Based upon the data input from the sensors  20  and the other various systems and sensors mentioned above the ECU  24  calculates an confidence factor (CF) that the object  28  is a pedestrian. If the confidence factor (CF) is greater than a predetermined reaction threshold (RT) the pedestrian protection system  12  enacts avoidance measures. The pedestrian protection system  12  may use kinematic data to compute the potential impact and send one or more safety and response signals to the various vehicle systems  14 A-D,  16  and  18  to initiate an action that will mitigate and/or prevent the pending impact. These actions may include, sounding a horn, flashing a rear facing light, pre-tensioning the seat belts, pre-charging the brakes, deploying a bumper to an extended collision position, lowering a body height of the vehicle  10 , and braking or steering the vehicle  10 , etc. 
         [0017]    The ECU  24  monitors data from the GPS  26  to determine if the vehicle  10  is in an area of increased pedestrian presence, e.g. close to points of interest such as theaters, arena, school zones, airports, etc. If the ECU  24  determines the vehicle  10  is in an area of increased pedestrian presence the ECU can lower the required reaction threshold (RT) that is required for a reaction from the vehicle  10 . Thus, the vehicle  10  will react at a lower confidence factor (CF) in areas of increased pedestrian presence. Conversely, in areas of decreased pedestrian presence the required reaction threshold (RT) may be increased. The system  12  will require a higher confidence factor (CF) before changing actions of the vehicle  10 . For example, on an expressway where pedestrians are not typically found and unwarranted braking is highly noticeable. Of course, the pedestrian protection system  12  will still react if the confidence factor (CF) that an object  28  is a pedestrian exceeds the increased reaction threshold (RT). Thus, the pedestrian protection system  12  still responds to protect pedestrians and has a decreased number of false detections resulting in unwarranted responses by the vehicle  10 . 
         [0018]    Alternatively, rather than increasing or decreasing the reaction threshold (RT) when in areas of low or high pedestrian presence the pedestrian protection system  12  may use the GPS data to increase or decrease the confidence factor (CF) an according amount. 
         [0019]    Another method of using the GPS data with the pedestrian protection system  12  may be to analyze the likelihood of the pedestrian crossing the vehicle path  10 . For example, the GPS data may be used to alter the ECU  24  decision on whether an impact is likely. For example, if the ECU  24  determines that the object  28  is likely a pedestrian, but that the GPS data indicates that the pedestrian is in a walkway, or the vehicle will be steering around a corner than the likelihood of impact may be decreased. The vehicle  10  reaction may be altered if the likelihood of impact is decreased based upon the pedestrian location and the GPS data. For example, the pedestrian protection system  12  may wait longer to brake the vehicle  10 . If the pedestrian protection system  12  still determines impact is likely the vehicle  10  may apply the brakes at a higher rate. Thus, early false detections and unnecessary vehicle  10  responses will be avoided while providing protection to pedestrians. 
         [0020]      FIG. 3  illustrates one embodiment of a method  36  for operating the pedestrian protection system  12 . With reference to  FIG. 1 , the method  36  for operating the pedestrian protection system  12  is described below. Data is sent from various systems and sensors  20  for the vehicle  10  to the ECU module  24 , step  38 . The ECU  24  monitors and processes the various data to determine if an object  28  is detected, step  40 . The ECU  24  analyzes the various data, i.e. image analysis, to calculate a confidence factor (CF) that the object  28  detected is a pedestrian, step  42 . Using the GPS  26  data the ECU  24  determines if the vehicle  10  is located in an area of increased pedestrian presence, decreased pedestrian presence, or an indeterminate area. If the vehicle  10  is in an area of decreased pedestrian presence the ECU  24  increases the reaction threshold (RT) for the pedestrian protection system  12 , step  46 . If the vehicle  10  is in an area of increased pedestrian presence the ECU  24  decreases the reaction threshold (RT) for the pedestrian protection system  12 , step  48 . If the vehicle  10  is in an indeterminate area of pedestrian presence the ECU  24  uses the pre-selected reaction threshold (RT) for the pedestrian protection system  12 . 
         [0021]    The confidence factor (CF) is compared to the reaction threshold(RT), step  50 . If the confidence factor (CF) is below the reaction threshold (RT) no reaction is necessary. The ECU  24  continues to monitor the data from the sensors  20  for pedestrian presence, step  38 . If the confidence factor (CF) is above the reaction threshold (RT) action may be necessary. The ECU  24  determines is an impact with the object  28  is likely to occur, step  52 . This information is based upon the position of the object  28  and the position and direction of travel for the vehicle  10 . 
         [0022]    If an impact is considered likely the ECU  24  may further compare the position of the object/pedestrian  28  with the data from the GPS  26 . The GPS  26  data may be used to alter the likelihood of an impact with the object/pedestrian  28 . For example, the GPS  26  data may indicate that the object/pedestrian  28  appears to be in the oncoming path of the vehicle  10 , but the road curves and the vehicle  10  will shortly be changing directions. In such an instance immediate braking of the vehicle  10  may not be necessary and a warning to the driver may be sufficient. Additional data such as the time of day, time of year, weather, etc. can also be used. 
         [0023]    Based upon the ECU  24  analysis of the GPS data the ECU will determine that impact is actually not likely, and no reaction by the pedestrian protection system  12  is required. The ECU  24  continues to monitor the sensor data, step  38 . Alternately the ECU  24  may determine that the standard response by the system  12  is preferable under the circumstances, step  56 . Finally, the ECU  24  may alter the vehicle  10  response by increasing or decreasing the reaction of the vehicle  10  based upon whether the GPS  26  data makes impact with the object/pedestrian  28  more or less likely, step  58 . 
         [0024]    At least one of a first safety signal and a first vehicle response signal are sent from the ECU  24 , step  54 . The first safety signal initiates at least one warning or device to prepare and protect the occupants of the vehicle  10  and the first vehicle response signal initiates at least one response to proactively prepare the vehicle  10  from a possible impact. A driver warning signal may be an auditory signal, a visual signal, such as activating a warning lamp, a haptic signal, such as a steering wheel vibration, or a combination of these signals. The driver warning signal may be provided to the vehicle operator with sufficient time to allow the driver to preemptively adjust the operation of the vehicle  10  in order to avoid the impact, such as by braking or steering the vehicle  10  toward another area. 
         [0025]    The safety device may be one of a seat belt restraint system, an airbag deployment system, a head restraint system, or other system designed to protect an occupant within passenger compartment. Pre-activating the safety device with the first safety signal would therefore include, pre-tensioning seat belts, pre-charging an airbag restraint, and pre-charging a head support system. 
         [0026]    In addition the pedestrian protection system  12  may also send a response signal to at least one vehicle  10  system to prepare the vehicle  10  for an impact. The first response signal may include, pre-charging the brakes, deploying a bumper to an extended collision position, lowering a body height of the vehicle  10 , and braking or steering the vehicle  10 . If the ECU  24  for the pedestrian protection system  12  detects that further action is required further safety and/or a response signals may also be sent, shown at  58 . 
         [0027]    The response signal initiates at least one response that changes the state of the vehicle  10  to prepare the vehicle  10  for or avoid a possible impact and has the primary purpose to reduce or eliminate injury to the pedestrian. However, ideally the vehicle  10  response also acts to protect the passengers of the vehicle  10  as well. 
         [0028]    Based on the current information the system  12  may indicates a response is not required by the vehicle  10 . However, the system  12  continues monitoring the data from the ECU  24 , step  38 . Thus, changing conditions of the vehicle  10 , confidence factor (CF) or other information may allow for the system  12  to provide a different reaction as the vehicle  10  is traveling and the data used by the ECU  24  is changing. 
         [0029]    While the best modes for carrying out the invention have been described in detail the true scope of the disclosure should not be so limited, since those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.