Patent Publication Number: US-2022227289-A1

Title: External notification system and external notification method

Description:
BACKGROUND 
     Field 
     The following description relates to an external notification system and an external notification method. 
     Description of Related Art 
     When driving a vehicle, a driver may come across a situation in which he or she is forced to stop the vehicle. One example of such a situation would be when a police officer orders the driver to stop the vehicle at a checkpoint or the like. Under such a situation, for example, when the police officer asks questions through the window while the driver is seated in the driver seat, the driver may be ordered to place both hands where they can be seen by the police officer to indicate that the driver is not taking a suspicious action. However, if the hands of the driver cannot be seen clearly by the police officer due to one reason or another such as a dark condition, the police officer may not understand what the driver is intending to do or how the driver is behaving. This may lead to a trouble that compromises the safety of the driver. Another example would be when the driver is forced to stop his or her vehicle by another driver with road rage. In this case, the safety of the driver may also be compromised after stopping the vehicle. For example, the vehicle may be hit from the rear by a following vehicle when suddenly stopping. 
     There is a conventional system that determines, for example, whether the hands of the driver are on the steering wheel of the vehicle and notifies the driver of the determination result (US Patent Application Publication No. US2011/0246028). Nonetheless, there is no system that ensures the safety of the driver by readily and promptly notifying the present situation of the driver to a person outside the vehicle (police officer in first situation, and driver of following vehicle in second situation). 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one aspect, an external notification system includes a first detector, a controller, and an information output device. The first detector detects when a body part of a driver is in contact with or proximate to a notification triggering portion located inside a vehicle and outputs a first detection signal. The controller generates a notification control signal based on the first detection signal. The information output device outputs external notification information based on the notification control signal over a period in which the body part is in contact with or proximate to the notification triggering portion. 
     In another aspect, an external notification method includes steps of detecting when a body part of a driver is in contact with or proximate to a notification triggering portion located inside a vehicle; generating a notification control signal based on the detection of contact or proximity of the body part; outputting external notification information based on the notification control signal over a period in which the body part is in contact with or proximate to the notification triggering portion; detecting when the body part is separated from the notification triggering portion; and stopping the output of the external notification information based on the detection that the body part is separated from the notification triggering portion. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic block diagram showing an exemplary external notification system in accordance with an embodiment. 
         FIG. 2  is a schematic block diagram showing exemplary elements of the external notification system shown in  FIG. 1 . 
         FIG. 3  is a timing diagram illustrating an exemplary external notification process in accordance with an embodiment. 
         FIG. 4  is a schematic diagram showing one example of a vehicle including the external notification system. 
         FIG. 5  is a schematic diagram showing an operational example of a grip sensor in accordance with an embodiment. 
         FIG. 6  is a schematic diagram showing an exemplary information output device in accordance with an embodiment. 
         FIG. 7  is a schematic diagram showing an exemplary arrangement pattern of multiple grip sensors. 
         FIG. 8  is a schematic diagram showing another exemplary arrangement pattern of the multiple grip sensors. 
         FIG. 9A  is a graph illustrating an exemplary grip determination process that uses a threshold value. 
         FIG. 9B  is a schematic diagram showing a grip state in which four fingers are separated from a steering wheel. 
         FIG. 9C  is a schematic diagram showing a grip state in which one finger is separated from the steering wheel. 
         FIG. 9D  is a schematic diagram showing a complete grip state in which all fingers are gripping the steering wheel. 
         FIG. 10  is a graph illustrating another exemplary grip determination process. 
         FIG. 11  is a flowchart illustrating an exemplary external notification method in accordance with an embodiment. 
         FIG. 12  is a flowchart illustrating an exemplary external notification process that includes a driver status record process. 
     
    
    
     Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     This description provides a comprehensive understanding of the methods, apparatuses, and/or systems described. Modifications and equivalents of the methods, apparatuses, and/or systems described are apparent to one of ordinary skill in the art. Sequences of operations are exemplary, and may be changed as apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Descriptions of functions and constructions that are well known to one of ordinary skill in the art may be omitted. 
     Exemplary embodiments may have different forms, and are not limited to the examples described. However, the examples described are thorough and complete, and convey the full scope of the disclosure to one of ordinary skill in the art. 
       FIG. 1  is a schematic block diagram showing an exemplary external notification system  10  in accordance with an embodiment. 
     The external notification system  10  includes a controller  12  and a first detector  14 . The controller  12  controls processing performed by the entire external notification system  10  in a centralized manner. The first detector  14  is connected to the controller  12 . When the first detector  14  detects that a body part  18  of a driver is in contact with or in the proximity of a notification triggering portion  16 , which is located inside a vehicle  1  (refer to  FIGS. 4 and 5 ), the first detector outputs a first detection signal  20  to the controller  12 . 
     In the present disclosure, the term “notification triggering portion” refers to a specified position inside the vehicle designated as a position that starts an external notification process performed by the external notification system  10 , which will be described later. The notification triggering portion  16  may be designated to any member, component, or part of member or component of the vehicle  1 . 
     In one example, a steering wheel of the vehicle  1  is designated as the notification triggering portion  16 . However, the notification triggering portion  16  is not limited to the steering wheel and may be, for example, part of a dashboard located frontward from the steering wheel. Alternatively, in correspondence with the application to which the functionality of the external notification system  10  is applied, an armrest of the driver seat, an assist grip that can be held by the driver, or any other portion near the driver seat may be designated as the notification triggering portion  16 . Hereafter, the notification triggering portion  16  may be referred to as the steering wheel  16  to facilitate understanding. 
     The body part  18  of the driver may be any part of the body that can take an action for contacting the notification triggering portion  16 . In one example, the first detector  14  detects a hand of the driver as the body part  18  that is in contact with or in the proximity of the notification triggering portion  16 . However, the body part  18  is not limited to a hand and may be a finger, an elbow, or a foot of the driver in correspondence with the application to which the functionality of the external notification system  10  is applied. Hereafter, the body part  18  may be referred to as the hand  18  to facilitate understanding. 
     In the present disclosure, the phrase “in contact with” refers to a state in which the body part  18  is in direct contact with the notification triggering portion  16 , and the phrase “in the proximity of” refers to a state in which the body part  18  is in indirect contact, or non-contact, with the notification triggering portion  16 . The first detector  14  detects when the body part is in contact with, in the proximity of, or both of in contact with and in the proximity of the notification triggering portion  16 . 
     In one example, the first detector  14  detects when the hand  18  of the driver is in contact with or in the proximity of the steering wheel  16  and outputs the first detection signal  20 . The controller  12  generates (makes active) a notification control signal  22  based on the first detection signal  20 . 
     The external notification system  10  further includes a second detector  24  and an information output device  26  that are connected to the controller  12 . The second detector  24  detects when the vehicle  1  has stopped and outputs a second detection signal  28  to the controller  12 . The information output device  26  outputs external notification information  30  based on the notification control signal  22  over a period in which the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . 
     In  FIG. 1 , the external notification system  10  includes the second detector  24 . However, the external notification system  10  does not necessarily have to include the second detector  24  as long as the controller  12  receives a signal indicating that the vehicle  1  has stopped. 
     In some embodiments, the controller  12  generates the notification control signal  22  based on the first detection signal  20  and the second detection signal  28 . In this manner, the information output device  26  outputs the external notification information  30  over a period in which the vehicle  1  is stopped and the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . 
     In the present disclosure, the term “external notification information” refers to information issued from the vehicle  1  to the outside of the vehicle  1  and includes any information that is transmitted through a display, sound, or a combination of a display and sound. The display may be continuous lighting, intermittent lighting, presentation of an image or a video, or a combination of the above. 
     The information output device  26  may be any existing device or dedicated device that can issue the external notification information  30  from the vehicle  1 . The information output device  26  outputs the external notification information  30  over a period in which the first detector  14  detects contact or proximity of the body part  18 . Thus, when the external notification information  30  is output from the vehicle  1  (information output device  26 ), the vehicle  1  is stopped and the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . 
     If necessary, the external notification system  10  may further include a driver status recorder  32  that is connected to the controller  12 . The driver status recorder  32  records the driver status while the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . 
     In some embodiments, the driver status may be shown by a video of the body part  18  that is in contact with or in the proximity of the notification triggering portion  16 . The driver status is shown by, for example, a video of the driver holding the steering wheel  16  with the hand  18 . In addition to or instead of the above video, the driver status may be shown by a video of the entire driver seat or the entire vehicle interior including the driver. In addition to or instead of the above video, the driver status may be shown by a video of the person (e.g., police officer or another involved person) to whom the driver is speaking through the window from the driver seat. In addition to or instead of the above video, the driver status may be shown by a video of unspecified persons or other vehicles near the vehicle  1 . 
     In some embodiments, the controller  12  activates the driver status recorder  32  at a time point at which the first detection signal  20  has been output over a predetermined duration. In the example shown in  FIG. 1 , the controller  12  activates the driver status recorder  32  at a time point at which the first detection signal  20  has been output over a predetermined duration while the second detection signal  28  is output. Therefore, the recording of the driver status begins at a time point at which the hand  18  of the driver has been in contact with or in the proximity of the steering wheel  16  over the predetermined duration while the vehicle  1  is stopped. 
     In some embodiments, the controller  12  continues recording with the driver status recorder  32  even after the output of the first detection signal  20  (detection of body part  18  being in contact with or in proximity of notification triggering portion  16 ) is stopped until a specified recording stopping condition is satisfied. In the example shown in  FIG. 1 , the controller  12  stops the driver status recorder  32  at a time point at which the output of the second detection signal  28  is stopped. Therefore, the recording of the driver status is stopped, for example, when the driver starts moving the vehicle  1 . 
       FIG. 2  is a schematic block diagram showing exemplary elements of the external notification system  10  shown in  FIG. 1 . 
     The controller  12  includes one or more processors  42  and a memory  44 . The memory  44  stores commands (computer programs) that can be executed by the processor  42  to perform an external notification process. The processor  42  may include a central processing unit (CPU). In addition to or instead of the CPU, the processor  42  may include a graphic processing unit (GPU), exclusive hardware such as an application specific integrated circuit (ASIC), or a combination of the above. The memory  44  includes any medium such as a random-access memory (RAM), a read-only memory (ROM), an optical storage device, a magnetic storage device, or a flash memory that is accessible by a computer (processor  42 ). 
     The controller  12  further includes a timer  46 . The controller  12  uses the timer  46  to measure the time elapsed from a time point at which the first detector  14  starts to output the first detection signal  20 . Then, the controller  12  determines whether the first detection signal  20  has been output for the predetermined duration, that is, whether the body part  18  has been in contact with or been in the proximity of the notification triggering portion  16  over the predetermined duration. 
     The first detector  14  includes a sensor system  52 . The sensor system  52  includes one or more contact or proximity sensors  54  that detect when the body part  18  is in contact with or in the proximity of the notification triggering portion  16  and output a sensor signal  56  (first detection signal  20 ). 
     Each of the contact or proximity sensors  54  includes, for example, at least one of a capacitive sensor, a pressure sensor, and a mechanical switch. The capacitive sensor measures changes in capacitance to detect when the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . The pressure sensor measures pressure changes to detect when the body part  18  is in contact with the notification triggering portion  16 . The mechanical switch includes a mechanical component (e.g., push-button) that is operable by the driver and arranged on the notification triggering portion  16 . The mechanical switch detects when the body part  18  is in contact with the notification triggering portion  16  in response to an operation by the driver. 
     As shown in  FIGS. 4, 5, and 7 , in some embodiments, the one or more contact or proximity sensors  54  are arranged inside the steering wheel  16  as grip sensors each including a capacitive sensor. Hereafter, the contact or proximity sensors  54  may be referred to as the grip sensors  54 . 
     The steering wheel  16  is substantially annular, and the grip sensors  54  include a first grip sensor  54 A and a second grip sensor  54 B. The first grip sensor  54 A is disposed in a first region of the steering wheel  16 , and the second grip sensor  54 B is disposed in a second region of the steering wheel  16 . The first region may occupy approximately one-half of the steering wheel  16  in the circumferential direction, and the second region may occupy the remaining approximately one-half of the steering wheel  16  in the circumferential direction. As shown in  FIGS. 5 and 7 , the first grip sensor  54 A detects when the steering wheel  16  is being held by a right hand  18 A and outputs a first sensor signal  56 A (first detection signal  20 ). In the same manner, the second grip sensor  54 B detects when the steering wheel  16  is being held by a left hand  18 B and outputs a second sensor signal  56 B (first detection signal  20 ). 
     As shown in  FIG. 2 , the first detector  14  may include a camera system  62 , if necessary. In some embodiments, the camera system  62  includes a camera  64  and an image processing unit  66 . The image processing unit  66  may be incorporated in the camera  64 . The camera  64  generates image data of a driver seat region including the notification triggering portion  16 . The image processing unit  66  obtains image data from the camera  64  and detects when the body part  18  is in contact with or in the proximity of the notification triggering portion  16  from the image data. Based on the detection, the camera system  62  outputs a detection signal  68  (first detection signal  20 ). The camera  64  may be, for example, an omnidirectional camera that captures images over 360 degrees in all directions, a camera that captures images at a specified viewing angle, or any image capturing device. As shown in  FIG. 4 , the camera  64  may be, for example, mounted on the dashboard of the vehicle  1 . 
     In  FIG. 2 , the first detector  14  includes both the sensor system  52  and the camera system  62 . However, the first detector  14  may include only one of the sensor system  52  or the camera system  62 . 
     In some embodiments, the second detector  24  includes a shift position sensor  72  that detects the position of a shift lever  82 . When the shift position sensor  72  detects that the shift lever  82  is in a parking position, the shift position sensor  72  outputs a detection signal  74  (second detection signal  28 ). The second detector  24  may include a vehicle speed sensor instead of the shift position sensor  72 . 
     The information output device  26  includes an indicator  92 , a display  94 , a horn  96 , a speaker  98 , or any combination of the indicator  92 , the display  94 , the horn  96 , and the speaker  98 . 
     For example, the indicator  92  includes turn signals, a hazard warning signal, other vehicle lights, a dedicated indicator, or any combination of the above signals and lights. As shown in  FIGS. 4 and 6 , an example of the dedicated indicator may be the indicator  92  arranged along the periphery of a side mirror  102  and configured to be illuminated continuously or intermittently. 
     The display  94  may use, for example, at least part of the windshield or the rear window as a screen. Alternatively, the display  94  may be an image display that is employed in the side mirror  102 . Any display device may be used as the display  94  as long as the display shows images or videos that can be seen from outside the vehicle  1 . 
     The driver status recorder  32  includes the camera system  62 . For example, the camera system  62  may be shared by the driver status recorder  32  and a first detector  14 . In other words, the first detector  14  may use the camera system  62  of the driver status recorder  32  to detect when the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . 
     An exemplary external notification process in accordance with an embodiment will now be described with reference to  FIGS. 1 to 3 .  FIG. 3  is a timing diagram illustrating the exemplary external notification process. 
     At time t 1 , the second detector  24  detects that the vehicle  1  has stopped and outputs the second detection signal  28 . For example, the shift position sensor  72  detects that the shift lever  82  is in the parking position. 
     At time t 2 , the first detector  14  detects that the body part  18  of the driver is in contact with or in the proximity of the notification triggering portion  16  and outputs the first detection signal  20 . For example, the grip sensors  54  ( 54 A and  54 B) detect that the steering wheel  16  is being held by both hands  18  ( 18 A and  18 B) of the driver (refer to  FIG. 5 ). 
     The controller  12  generates (makes active) the notification control signal  22  based on the first detection signal  20  and the second detection signal  28 . Further, the controller  12  uses the timer  46  to measure the time elapsed from time t 2  when the first detector  14  starts to output the first detection signal  20 . The information output device  26  outputs the external notification information  30  based on the notification control signal  22  from the controller  12 . For example, the indicator  92  of the side mirror  102  is illuminated continuously or intermittently (refer to  FIG. 6 ). 
     At time t 3 , the controller  12  determines that the first detection signal  20  has been output over duration T 1  and activates the driver status recorder  32 . In the present example, the recording of the driver status is started at time t 3  when the two hands  18  ( 18 A and  18 B) of the driver have been in contact with or in the proximity of the steering wheel  16  over duration T 1  while the vehicle  1  is stopped. 
     At time t 4 , the first detector  14  detects that the body part  18  of the driver is separated from the notification triggering portion  16  and stops the output of the first detection signal  20 . In the present example, the grip sensors  54  ( 54 A and  54 B) detect when the two hands  18  ( 18 A and  18 B) of the driver are separated from the steering wheel  16 . 
     The controller  12  makes the notification control signal  22  inactive at time t 4  when the output of the first detection signal  20  is stopped. In response, the information output device  26  stops the output of the external notification information  30 . In the present example, the continuous or intermittent illumination of the indicator  92  of the side mirror  102  (refer to  FIG. 6 ) is stopped. In this manner, the information output device  26  outputs the external notification information  30  over a period in which the notification control signal  22  is active. 
     At time t 5 , the second detector  24  detects that the vehicle  1  is starting to move and stops the output of the second detection signal  28 . In the present example, the shift position sensor  72  detects that the shift lever  82  has been released from the parking position (for example, shift lever  82  shifted to drive position). 
     The controller  12  stops the recording of the driver status at time t 5  when the output of the second detection signal  28  is stopped. The stopping of the output of the second detection signal  28  is one example of a recording stopping condition. 
       FIG. 8  is a schematic diagram showing another exemplary arrangement pattern of the grip sensors  54  ( 54 A 1 ,  54 A 2 ,  54 A 3 ,  54 B 1 ,  54 B 2 , and  54 B 3 ). 
     As shown in  FIG. 8 , the grip sensors  54 A 1  to  54 A 3  are arranged in the first region of the steering wheel  16  (approximately one-half of steering wheel  16  in circumferential direction). In the same manner, as indicated in the parentheses in  FIG. 8 , the grip sensors  54 B 1  to  54 B 3  are arranged in the second region of the steering wheel  16  (remaining one-half of steering wheel  16  in circumferential direction). The grip sensors  54 A 1  to  54 A 3  and  54 B 1  to  54 B 3  each include a capacitive sensor in the same manner as the grip sensors  54 A and  54 B shown in  FIG. 7 . 
     As shown in  FIG. 8 , the steering wheel  16  has a circular cross section extending in a radial direction of the steering wheel  16 . The grip sensors  54 B 1  to  54 B 3  are disposed in the first region of the steering wheel  16  and are adjacent to one another in the circumferential direction of the circular cross section. For example, the grip sensors  54 A 1  to  54 A 3  respectively detect when the palm of the right hand  18 A, the proximal side of the fingers of the right hand  18 A, and the distal side of the fingers of the right hand  18 A are in contact with or in the proximity of the steering wheel  16  and output a sensor signal. In the same manner, the grip sensors  54 B 1  to  54 B 3  are disposed in the second region of the steering wheel  16  adjacent to one another in the circumferential direction of the circular cross section to respectively detect when the palm of the left hand  18 B, the proximal side of the fingers of the left hand  18 B, and the distal side of the fingers of the left hand  18 B are in contact with or in the proximity of the steering wheel  16  and output a sensor signal. 
     Such an arrangement pattern allows for determination of whether the steering wheel  16  is being held by the two hands  18 A and  18 B. For example, when a foot or an arm of the driver is in contact with the steering wheel  16 , one of the grip sensors  54 A 1  to  54 A 3  or one of the grip sensors  54 B 1  to  54 B 3  outputs a sensor signal and the rest of the grip sensors do not output sensor signals. In contrast, when the steering wheel  16  is being held by the two hands  18 A and  18 B, every one of the grip sensors  54 A 1  to  54 A 3  and  54 B 1  to  54 B 3  outputs a sensor signal. For example, when every one of the grip sensors  54 A 1  to  54 A 3  and  54 B 1  to  54 B 3  outputs a sensor signal, the first detector  14  outputs the first detection signal  20 . This allows the first detector  14  to recognize that the body part  18 , which is in contact with the steering wheel  16 , is a hand. 
       FIG. 9A  is a graph illustrating an exemplary grip determination process that uses threshold value Th. In  FIG. 9A , the vertical axis indicates the capacitance of the grip sensor  54 A in correspondence with three grip states of the right hand that are shown in the direction of the horizontal axis in  FIGS. 9B, 9C, and 9D . 
     In some embodiments, when the capacitance detected by the grip sensor  54 A is greater than or equal to the threshold value Th (first threshold value), the controller  12  determines that the steering wheel  16  is being held by the right hand  18 A of the driver without any finger being separated from the steering wheel  16 . Further, when the capacitance detected by the grip sensor  54 B is greater than or equal to the threshold value Th (second threshold value), the controller  12  determines that the steering wheel  16  is being held by the left hand  18 B of the driver without any finger being separated from the steering wheel  16 . The first threshold value the first threshold value and the second threshold value may be the same or different. 
     As shown in  FIG. 9B , in a grip state in which four fingers are separated from the steering wheel  16 , the capacitance C 1  is much lower than the threshold value Th. As shown in  FIG. 9C , in a grip state in which one finger is separated from the steering wheel  16 , the capacitance C 2  is higher than the capacitance C 1  but still lower than the threshold value Th. As shown in  FIG. 9D , in a complete grip state in which all fingers are gripping the steering wheel  16 , the capacitance C 3  is higher than the threshold value Th. The controller  12  may compare the capacitance (sensor signal) of the grip sensor  54 A with the threshold value Th to determine whether the steering wheel  16  is in the complete grip state ( FIG. 9D ). The same grip determination process can be applied to the grip sensor  54 B. 
       FIG. 10  is a graph illustrating another exemplary grip determination process. In  FIG. 10 , the horizontal axis indicates time and the vertical axis indicates the capacitance of the grip sensor  54 . 
     For example, if a conductor is in contact with the steering wheel  16  instead of the hand  18 , the capacitance (sensor signal) of the grip sensor  54  is a constant value that does not fluctuate. In contrast, when the hand  18  is in contact with the steering wheel  16 , the capacitance (sensor signal) of the grip sensor  54  fluctuates finely over time. The controller  12  may determine whether the steering wheel  16  is being held by the hand  18  of the driver from such fine fluctuation of the sensor signal over time. 
       FIG. 11  is a flowchart illustrating an exemplary external notification method in accordance with an embodiment. The flowchart starts while the vehicle  1  is stopped. 
     In step S 10 , the first detector  14  detects that the body part  18  of the driver is in contact with or in the proximity of the notification triggering portion  16  in the vehicle  1  (timing t 2  in  FIG. 3 ). The controller  12  provides the information output device  26  with an active notification control signal  22 . 
     In step S 12 , the information output device  26  outputs the external notification information  30  based on the notification control signal  22  over a period in which the body part  18  is in contact with or in the proximity of the notification triggering portion  16  (after time t 2  in  FIG. 3 ). 
     In step S 14 , the first detector  14  detects that the body part  18  is separated from the notification triggering portion  16  (timing t 4  in  FIG. 3 ). The controller  12  makes the notification control signal  22  inactive. 
     In step S 16 , the information output device  26  stops the output of the external notification information  30  in response to the inactive notification control signal  22 . 
       FIG. 12  is a flowchart illustrating an exemplary external notification process that includes a driver status recording process. 
     In step S 20 , the controller  12  determines whether the vehicle  1  has stopped based on the second detection signal  28  from the second detector  24 . For example, the controller  12  determines that the vehicle  1  has stopped when the shift position sensor  72  detects that the shift lever  82  is in the parking position. 
     In step S 22 , the controller  12  determines whether the body part  18  is in contact with or in the proximity of the notification triggering portion  16 . For example, when the grip sensor  54  detects that the steering wheel  16  is being held by the two hands  18  of the driver, the controller  12  makes the notification control signal  22  active. 
     In step S 24 , the controller  12  provides the information output device  26  with the active notification control signal  22 , and the information output device  26  outputs the external notification information  30  in response to the notification control signal  22 . For example, the indicator  92  of the side mirror  102  is illuminated continuously or intermittently. 
     In step S 26 , the controller  12  determines whether the body part  18  has been in contact with or in the proximity of the notification triggering portion  16  over the predetermined duration T 1 . When the predetermined duration T 1  elapses, the controller  12  activates the driver status recorder  32  in step S 28 . In this manner, in the present example, the camera system  62  starts recording the driver status when the two hands  18  of the driver have been in contact with or in the proximity of the steering wheel  16  over duration T 1  while the vehicle  1  is stopped. 
     In step S 30 , the controller  12  determines whether the body part  18  has been separated from the notification triggering portion  16 . In the present example, when the grip sensor  54  detects that at least one of the hands  18  of the driver has been separated from the steering wheel  16 , the controller  12  makes the notification control signal  22  inactive. 
     In step S 32 , the information output device  26  stops the output of the external notification information  30  in response to the inactive notification control signal  22 . In the present example, the continuous or intermittent illumination of the indicator  92  of the side mirror  102  is stopped. In this manner, the information output device  26  outputs the external notification information  30  over a period in which the notification control signal  22  is active. 
     When a negative determination is given in step S 26 , the controller  12  determines in step S 34  whether the body part  18  has been separated from the notification triggering portion  16  in the same manner as in step S 30 . When an affirmative determination is given in step S 34 , the controller  12  proceeds to step S 35  and stops the output of the external notification information  30 . 
     In step S 36 , the controller  12  determines whether the vehicle  1  is starting to move. In the present example, the controller  12  determines that the vehicle  1  is starting to move when the shift position sensor  72  detects that the shift lever  82  is in a drive position. In step S 38 , the controller  12  stops the driver status recorder  32 . In this manner, in the present example, the camera system  62  stops recording the driver status. 
     The operation of the external notification system  10  in accordance with an embodiment will now be described. 
     In one potential situation, the driver may be ordered to stop the vehicle  1  by a police officer at a checkpoint or the like. Under such a situation, for example, when the police officer questions the driver through the window while the driver is seated in the driver seat, the police officer may ask the driver to place both hands  18  where they can be seen to indicate that the driver is not taking a suspicious action. 
     In this case, when the driver is holding the steering wheel  16  with both hands  18 , the grip sensor  54  detects the gripping of the steering wheel  16 , and the indicator  92  of the side mirror  102  is illuminated continuously or intermittently. When the police officer confirms such a continuous or intermittent illumination of the indicator  92  of the side mirror  102 , the police officer will acknowledge that the driver is holding the steering wheel  16  with both hands  18 . Specifically, the police officer will be notified of such a notification scheme in advance. Thus, by checking continuous or intermittent illumination of the indicator  92 , the police officer can acknowledge that the steering wheel  16  is being held without the need to directly look at the driver seat. This avoids troubles that may result from interactions between the driver and a police officer. 
     Further, when the driver continues to hold the steering wheel  16  with both hands  18  over the predetermined duration T 1 , the camera system  62  is activated to start recording the driver status. The recording of the driver status continues even after the driver releases both hands  18  from the steering wheel  16  until the shift lever  82  is shifted to the drive position. Since interactions between the driver and the police officer are recorded, the driver will feel a sense of security. 
     In another potential situation, another driver with road rage may force the driver to stop the vehicle  1 . In this case, the vehicle  1  may be hit from the rear by a following vehicle when suddenly stopping. 
     In such a case, when the driver holds the steering wheel  16  with both hands  18 , the grip sensor  54  detects gripping of the steering wheel  16  and continuously or intermittently illuminates the hazard warning signal, which is one example of the indicator  92 . The continuous or intermittent illumination of the hazard warning signal will notify the driver of a following vehicle that the vehicle  1  in front has stopped. This avoids being hit from the rear by a following vehicle and ensures the safety of the driver. 
     Further, when the driver continues to hold the steering wheel  16  with both hands  18  over the predetermined duration T 1 , the camera system  62  is activated to start recording the driver status. The recording of the driver status continues even after the driver releases both hands  18  from the steering wheel  16  until the shift lever  82  is shifted to the drive position. Since interactions between the driver and the driver with road rage are recorded, the driver will feel a sense of security. 
     The external notification system  10  according to an embodiment has the following advantages. 
     (1) The information output device  26  outputs the external notification information  30  to the outside of the vehicle  1  over a period in which the body part  18  of the driver is in contact with or in the proximity of the notification triggering portion  16 . Therefore, a person outside the vehicle  1  can acknowledge the present status of the driver (body part  18  in contact with or in proximity of notification triggering portion  16  or vehicle  1  stopped) from the external notification information  30 . In this manner, the driver can inform the person outside the vehicle  1  about the present status of the driver without performing complicated operations. As a result, the driver can promptly convey his or her intention when interacting with the person outside the vehicle  1 . 
     (2) When the body part  18  of the driver is in contact with or in the proximity of the notification triggering portion  16  over the predetermined duration T 1 , recording of the driver status is started. In this manner, the driver status is recorded when the driver interacts with a person outside the vehicle  1 . Thus, the driver will feel a sense of security. Consequently, this ensures the safety of the driver. 
     (3) The recording of the driver status is continued until the vehicle  1  starts moving, for example, when the shift lever  82  is shifted to the drive position. In this manner, the driver can feel a sense of security. 
     (4) The steering wheel  16  is designated as the notification triggering portion  16 . In this case, the external notification information  30  is output when the driver simply holds the steering wheel  16  with both hands  18 . Therefore, the driver does not have to perform complicated operations to output the external notification information  30 . 
     (5) The first detector  14  includes the grip sensor  54  that detects when the steering wheel  16  is held by both hands  18  ( 18 A and  18 B) of the driver. Thus, the driver is further restricted from performing a false gripping action in which the driver holds the steering wheel  16  with one hand  18 . 
     (6) The grip sensor  54  includes the grip sensors  54 A 1  to  54 A 3  and  54 B 1  to  54 B 3  to detect when the steering wheel  16  is completely held by the entire hand  18  including the fingers. This configuration further restricts the driver from performing a false gripping action. 
     (7) The grip determination process that uses the threshold value Th is performed to further restrict the driver from performing a false gripping action. 
     (8) Fine fluctuations over time of the sensor signal (capacitance) of the grip sensor  54  are detected to further restrict the driver performing a false gripping action. 
     It should be apparent to those skilled in the art that the present disclosure may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the above embodiment may be embodied in the following forms. 
     (a) The first detector  14 , the second detector  24 , the information output device  26 , and the driver status recorder  32  do not have to be configured as shown in  FIG. 2 . 
     (b) The grip sensor  54  does not have to include a capacitive sensor. Further, the arrangement pattern of the grip sensors  54  in the steering wheel  16  is not limited to that of the above embodiment. For example, a single grip sensor  54  may be used. 
     (c) The external notification process illustrated in  FIG. 3  is an example and other control process may be employed. For example, the output of the external notification information  30  may be continued until the recording of the driver status is stopped. Alternatively, the recording of the driver status and the output of the external notification information  30  may be started simultaneously. 
     (d) The camera system  62  may be controlled in a modified manner. For example, the camera  64  may capture images of the outside of the vehicle  1  until gripping of the steering wheel  16  is detected, and the camera  64  may capture images of the inside of the vehicle  1  when gripping of the steering wheel  16  is detected or when the steering wheel  16  has been held over the predetermined duration T 1 . In this manner, the camera  64  may be controlled to switch image capturing areas. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although embodiment of the present invention has been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.