Patent Publication Number: US-2023158889-A1

Title: Vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to and the benefit of Japanese Patent Application No. 2021-189589 filed on Nov. 22, 2021, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a vehicle. 
     Description of the Related Art 
     Techniques for notifying drivers of the surrounding situation of the vehicles have been proposed. For example, Japanese Patent Laid-Open No. 2016-182892 describes an in-vehicle display device that displays an icon on a screen with a display position and a display color that depend on the direction of a pedestrian and with a size that depends on the distance between the pedestrian and the vehicle. 
     SUMMARY OF THE INVENTION 
     According to embodiment of the present invention, there is provided a vehicle comprising: a detector configured to detect an object at least ahead of the vehicle; and a display provided on an instrument panel of the vehicle and configured to display a signal at a position corresponding to a direction of the object detected by the detector, wherein the display includes a part recessed forward in a vehicle longitudinal direction in plan view. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a plan view of a vehicle according to an embodiment; 
         FIG.  2    is a view illustrating the interior configuration of the vehicle; 
         FIG.  3    is a perspective view illustrating the appearance of a display device; 
         FIG.  4    is a schematic diagram illustrating the structure of a display; 
         FIG.  5    is a diagram for explaining how the display is placed in the vehicle; 
         FIG.  6    is a diagram illustrating the hardware configuration of the vehicle V equipped with the display device; 
         FIG.  7    is a diagram illustrating an example situation in which the display device operates; 
         FIG.  8    is a forward view from the driver&#39;s seat of the vehicle in each state in the situation of  FIG.  7   ; 
         FIG.  9    is a forward view from the driver&#39;s seat of the vehicle in each state in the situation of  FIG.  7   ; 
         FIG.  10    is a flowchart illustrating a processing example of an ECU; 
         FIG.  11    is a diagram illustrating an example situation in which the display device operates; 
         FIG.  12    is a forward view from the driver&#39;s seat of the vehicle in each state in the situation of  FIG.  11   ; 
         FIG.  13    is a forward view from the driver&#39;s seat of the vehicle in each state in the situation of  FIG.  11   ; 
         FIG.  14 A  is a flowchart illustrating a processing example of an ECU; 
         FIG.  14 B  is a flowchart illustrating a processing example of an ECU; 
         FIG.  15    is a diagram illustrating an example situation in which the display device operates; 
         FIG.  16    is a forward view from the driver&#39;s seat of the vehicle in each state in the situation of  FIG.  15   ; 
         FIG.  17    is a forward view from the driver&#39;s seat of the vehicle in each state in the situation of  FIG.  15   ; 
         FIG.  18    is a flowchart illustrating a processing example of an ECU; and 
         FIG.  19    is a schematic diagram illustrating the configuration of an adjuster for the tension of the seat belt for the driver&#39;s seat according to an embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Recent improvement in driving assistance technology and electrification of vehicles is accompanied by an increasing trend in information provision to drivers. Increasing information provision to drivers may make the drivers feel annoyed or hinder the drivers from recognizing necessary information. Therefore, from the viewpoint of improving traffic safety, it is desirable that drivers can more easily recognize necessary information such as the surrounding situation of the vehicles. 
     An embodiment of the present invention provides the surrounding situation of a vehicle to the driver in an easy-to-recognize manner. 
     Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made an invention that requires all combinations of features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. 
     In addition, in each drawing, the X direction represents the longitudinal direction of a vehicle V, the Y direction represents the vehicle width direction of the vehicle V, and the Z direction represents the vertical direction of the vehicle V. In addition, in the present specification, expressions such as front/rear, left/right (lateral), and upper/lower indicate a relative positional relationship with respect to the vehicle body, and for example, expressions such as front and forward correspond to the +X direction, and expressions such as rear and rearward correspond to the —X direction. In addition, for example, expressions such as left and leftward correspond to the +Y direction, and expressions such as right and rightward correspond to the —Y direction. Similarly, expressions such as the inside of the vehicle body and the outside of the vehicle body (inside and outside of the vehicle) indicate a relative positional relationship with respect to the vehicle body. 
     &lt;Outline of Vehicle&gt; 
       FIG.  1    is a plan view of the vehicle V according to an embodiment. The vehicle V is equipped with a display device  1  to be described later. Here, a sedan-type four-wheeled passenger car is illustrated as the vehicle V, but the vehicle V may be another type of vehicle. 
     The vehicle V includes a detector  44  that detects an object at least ahead of the vehicle V. In the present embodiment, the detector  44  is a camera. The detector  44  is provided in the interior of the vehicle V, and captures an area ahead of the vehicle V, more specifically a detection angle range DA1, through a window  43  (front window). Note that millimeter wave radar, light detection and ranging (LIDAR), or the like may be used as the detector  44  in addition to the camera. Examples of objects that are detected by the detector  44  include objects that exist around the vehicle V and have a possibility of contact with the vehicle V, such as pedestrians, bicycles, parked vehicles, preceding vehicles, curbstones, or fallen objects on the road. In addition to objects, the detector  44  can also detect white lines or the like that define the traveling lane on which the vehicle V is traveling. 
       FIG.  2    is a view illustrating the interior configuration of the vehicle V as viewed forward from the driver&#39;s seat. Placed on the front side in the interior of the vehicle V is an instrument panel  2 , on which various interior components are provided. For example, the instrument panel  2  is provided with a meter panel  21  on which information such as the state or traveling status of the vehicle V is displayed, a navigation system  23  on which information related to map information or audio is displayed, and the like. In the present embodiment, the meter panel  21  is provided on the back side of a steering wheel  41  as viewed from the driver&#39;s seat, and the navigation system  23  is provided at the center in the width direction of the vehicle V. The instrument panel  2  also includes a meter visor  22  that covers the upper part of the meter panel  21 . The display device  1  is provided above the meter visor  22 . The configuration of the display device  1  will be described later. In the interior of the vehicle V, a line-of-sight monitor  45  (see  FIG.  6   ) that monitors the driver&#39;s line of sight is also provided. The line-of-sight monitor  45  can be placed on the upper side of the window  43 , on the instrument panel  2 , or the like. 
     &lt;Display Device&gt; 
     Reference is made to  FIG.  3    together with  FIG.  2   .  FIG.  3    is a perspective view illustrating the appearance of the display device  1 . The display device  1  includes a display  10  and a housing  12 . 
     The display  10  displays a signal related to an object around the vehicle V. Specifically, the display  10  is provided on the instrument panel  2  of the vehicle V, and displays a signal at a position corresponding to the direction of the object detected by the detector  44 . The display  10  is placed facing the rear of the vehicle V, and can be visually recognized by the driver seated in the driver&#39;s seat. More specifically, the display  10  is provided above the meter visor  22  included in the instrument panel  2 . With this arrangement, the display  10  is located where the display  10  is likely to stay in the driver&#39;s field of vision during driving, so that the driver can easily check the indication on the display  10  during driving. In addition, the signal can enter the lower part of the driver&#39;s view without blocking the view. Instead of above the meter visor  22 , the display  10  may be placed such that, for example, more than half of the display  10  is located on the driver&#39;s seat side relative to the center line of the vehicle V extending in the vehicle longitudinal direction. With the display  10  placed closer to the driver&#39;s seat in the vehicle width direction, the display  10  is likely to stay in the driver&#39;s view. In addition, as will be described in detail later, the display  10  in the present embodiment includes a plurality of light emitters  103  and a base portion  104  on which the light emitters  103  are arranged. The housing  12  is provided in front of the display  10  in the state where the display  10  is mounted on the vehicle V, and houses electronic circuit boards, electric wiring, and the like. 
     &lt;Structure of Display&gt; 
       FIG.  4    is a schematic diagram illustrating the structure of the display  10  as the display  10  is viewed from above in the state where the display device  1  is mounted on the vehicle V. With the following configuration, the display  10  displays a signal at a position corresponding to the direction of the object detected by the detector  44 . For the sake of simplicity, reference numerals for some of a plurality of components of the same kind are omitted from the drawing. 
     The base portion  104  is formed extending in the vehicle width direction as a whole and also extending to the front of the vehicle V as it goes inward in the width direction of the base portion  104 . In other words, the base portion  104  includes a part recessed forward in the vehicle longitudinal direction in plan view. The plurality of light emitters  103  are arranged on an arrangement surface  1041  which is a side surface of the base portion  104  facing the rear side in the vehicle longitudinal direction. In the present embodiment, the arrangement surface  1041  of the base portion  104  is formed in an arc shape recessed forward. Therefore, the plurality of light emitters  103  are arranged at predetermined intervals along a virtual arc AR1. Since the display  10  includes the part recessed forward in the vehicle longitudinal direction in plan view, the driver can readily recognize the correspondence between the direction of the object and a position on the display  10 . More specifically, the direction of the object as viewed from the vehicle V can be more accurately reflected in the signal indication on the display  10 . 
     In the present embodiment, the central angle CA1 of the arc AR1 corresponds to the detection angle range DA1 (see  FIG.  1   ) of the detector  44 . For example, the central angle CA1 of the arc AR1 and the detection angle range DA1 of the detector  44  may be set to 90 to 150 degrees, and more specifically to 120 degrees. Note that the central angle CA1 and the detection angle range DA1 can be regarded as corresponding to each other not only when these angles coincide with each other but also when the difference between these angles is within a predetermined range. For example, the difference between the central angle CA1 and the detection angle range DA1 may be within 5, 10, 20, or 30 degrees. 
     The plurality of light emitters  103  are arranged at predetermined intervals on the arrangement surface  1041  of the base portion  104 . That is, in the present embodiment, the plurality of light emitters  103  are provided along the circumferential direction of the arc AR1. The number of light emitters  103  and the interval therebetween can be changed as appropriate, and for example, may be set according to the detection error in the detector  44 . For example, the plurality of light emitters  103  may be arranged such that the angle formed by two virtual line segments each connecting the center Cl of the arc AR1 and one of two adjacent light emitters  103  of the plurality of light emitters  103  is equal to or larger than the detection error angle in the detector  44 . In the example of  FIG.  4   , the number of light emitters  103  and the interval therebetween may be set such that the angle θv1 formed by the two virtual line segments VL1 and VL2 respectively connecting the center Cl of the arc AR1 and the two adjacent light emitters  103   a  and  103   b  is equal to or larger than the detection error in the detector  44 . Consequently, it is possible to prevent the signal indication from flickering due to the influence of detection error in the detector  44 . 
     In the present embodiment, the display  10  displays a signal at a position corresponding to the direction of the object detected by the detector  44 . For example, if the detector  44  detects an object located in the direction of 45 degrees to the left with respect to the traveling direction of vehicle V, the light emitter  103   c  located in the direction of 45 degrees to the left with respect to the traveling direction of vehicle V as viewed from the center Cl of the arc AR1 emits light. Consequently, the driver can intuitively recognize the direction of the object. 
       FIG.  5    is a diagram for explaining how the display  10  is placed in the vehicle V. In the present embodiment, the display  10  is placed such that the angle formed by two virtual line segments each connecting one of the opposite ends of the display  10  in the vehicle width direction of the vehicle V and the eye point EP set in the vehicle V lies in the range of 25 to 30 degrees. Specifically, in plan view, the display  10  is placed such that the angle θv2 formed by the two virtual line segments VL3 and VL4 respectively connecting the ends  1042  and  1043  in the vehicle width direction of the arrangement surface  1041  and the eye point EP set in the vehicle V lies in the range of 25 to 30 degrees. As the eye point EP, for example, the reference eye point defined in Japanese Industrial Standards JIS D1702:1996 can be used. 
     If the size of the display  10  in the vehicle width direction is too large, that is, if the angle θv2 is too large, the signal displayed on the display  10  is unlikely to enter the driver&#39;s view. On the other hand, if the size of the display  10  in the vehicle width direction is too small, that is, if the angle θv2 is too small, it might be difficult to understand the correspondence between the direction of the object and the signal indication position on the display  10 . By placing the display  10  such that the angle θv2 lies within the above-described angle range, it is possible to achieve both the visibility of the signal and the ease of recognition of the correspondence to the indication position. 
     The above-mentioned range of the angle θv2 (25 to 30 degrees) is an example that is based on the assumption that the detection angle range DA1 of the detector  44  is around 120 degrees. The range of the angle θv2 may be set as appropriate according to the detection angle range DA1 of the detector  44 . For example, if the detection angle range DA1 of the detector  44  is relatively small (e.g. detection angle range DA1=20 degrees), setting the angle θv2 larger than the detection angle range DA1 cannot necessarily lead to an appropriate expression of the position of the object on the display  10 . Therefore, the angle θv2 may be set to be equal to or smaller than the detection angle range DA1. For example, if the detection angle range DA1 is 20 degrees, the display  10  may be provided such that the angle θv2 lies in the range of 15 to 20 degrees. On the other hand, if the angle θv2 is smaller than ⅕ of the detection angle range DA1, it may be difficult to match the signal indication position on the display  10  with the direction of the object ahead. Therefore, the angle θv2 may be set to be ⅕ or more of the detection angle range DA1. For example, if the detection angle range DA1 is 90 degrees, the angle θv2 may be set to 18 degrees or more. That is, the angle θv2 may be in the range of ⅕ of the detection angle range DA1 to the detection angle range DA1. Consequently, it is possible to appropriately associate the signal indication position on the display  10  with the direction of the object ahead. 
     Hardware Configuration Example 
       FIG.  6    is a diagram illustrating the hardware configuration of the vehicle V equipped with the display device  1 . The detector  44  and the display device  1  are as described above, and thus the description thereof is omitted. The line-of-sight monitor  45  monitors the driver&#39;s line of sight. The line-of-sight monitor  45  is, for example, a camera (driver monitoring camera) that captures an image of the driver. A GPS antenna  46  receives radio waves from GPS satellites in order to acquire the current location of the vehicle V. Specifically, the GPS antenna  46  receives radio waves including satellite coordinate data and time data from GPS satellites. A Vehicle-to-Pedestrian (V2P) communicator  47  acquires, from a pedestrian&#39;s information processing terminal  8  near the vehicle V, the location information and the like of the information processing terminal  8  through V2P communication in which communication is performed between the vehicle and the pedestrian terminal. 
     A control unit  3  is a unit that controls the vehicle V, and includes a plurality of ECUs  31  to  35  communicably connected by the in-vehicle network. Each ECU includes a processor represented by a CPU, a storage device such as a semiconductor memory, an interface with an external device, and the like. The storage device stores programs executed by the processor, data used by the processor for processing, and the like. Each ECU may include a plurality of processors, storage devices, interfaces, and the like. Alternatively, each ECU may include a dedicated integrated circuit such as an application-specific integrated circuit (ASIC) for each ECU to execute processing. 
     Functions assigned to each of the ECUs  31  to  35  will be described hereinbelow. Note that the number of ECUs and the functions assigned to the ECUs can be designed as appropriate and can be subdivided or integrated compared with the present embodiment. 
     The ECU  31  identifies the distance between the vehicle V and the detected object and the direction of the object as viewed from the vehicle V based on the detection result from the detector  44 . The ECU  32  identifies the driver&#39;s line of sight based on the detection result from the line-of-sight monitor  45 . The ECU  33  identifies the location of the vehicle V based on the data received by the GPS antenna  46  from GPS satellites. The ECU  34  identifies the distance between the vehicle V and the information processing terminal  8  and the direction of the information processing terminal  8  as viewed from the vehicle V from the location information of the information processing terminal  8  received from the information processing terminal  8  and the location of the vehicle V identified by the ECU  33 . The ECU  35  controls indication on the display device  1 . As will be described in detail later, for example, the ECU  35  causes the selected light emitter  103  to emit light based on the distance between the vehicle V and the object and the direction of the object as viewed from the vehicle V acquired from the ECU  31 . In addition, for example, the ECU  35  causes the selected light emitter  103  to emit light based on the distance between the information processing terminal  8  and the object and the direction of the information processing terminal  8  as viewed from the vehicle V acquired from the ECU  34 . 
     The information processing terminal  8  is a terminal carried by a pedestrian or the like. The information processing terminal  8  includes a processor represented by a CPU, a storage device such as a semiconductor memory, a communication device with an external device, and the like. The processor of the information processing terminal  8  controls the communication device of the information processing terminal  8  to transmit a wireless signal for short-range communication in a predetermined communication range by broadcast without designating a destination. The V2P communicator  47  of the vehicle V receives the wireless signal transmitted by the communication device of the information processing terminal  8 . 
     &lt;Operation of Display Device&gt; 
     Operation Example 1 
     Next, an operation example of the display device  1  during the travel of the vehicle V will be described.  FIG.  7    is a diagram illustrating an example situation in which the display device  1  operates.  FIGS.  8  to  9    are forward views from the driver&#39;s seat of the vehicle V in each state in the situation of  FIG.  7   . The illustrated situation shows that construction vehicles (hereinafter referred to as the vehicles  91  and  92 ) are parked as objects in an adjacent lane L 2  adjacent to a traveling lane L 1  on which the vehicle V is traveling, and the vehicle V is passing by the construction vehicles. 
     State ST 101  is a state in which the detector  44  has detected the vehicles  91  and  92  ahead of the vehicle V. At this time, on the display  10  of the display device  1 , a signal SG 1  is displayed at a position corresponding to the direction of the detected vehicles  91  and  92  as viewed from the vehicle V. That is, the light emitter  103  at the position corresponding to the direction of the detected vehicles  91  and  92  as viewed from the vehicle V is turned on. 
     State ST 102  is a state in which the vehicle V has slightly moved forward from state ST 101 . In state ST 102 , the distance between the vehicle V and the vehicles  91  and  92  in the vehicle width direction does not differ from that in state ST 101 , but the distance between the vehicle V and the vehicles  91  and  92  in the longitudinal direction is shorter than that in state ST 101 . Therefore, the direction of the vehicles  91  and  92  as viewed from the vehicle V is shifted to the left with respect to the traveling direction. Accordingly, on the display  10 , the signal SG 1  is displayed at a position on the left side of the signal SG 1  in state ST 101 . 
     State ST 103  is a state in which the vehicle V has further moved forward from state ST 102 . On the display  10 , the signal SG 1  is displayed at a position further on the left side of the signal SG 1  in state ST 102 . 
     State ST 104  is a state in which the vehicle V has slightly moved forward from state ST 103  and passed by the vehicles  91  and  92 . Because the vehicle  91  and the vehicle  92  are out of the detection angle range DA1 of the detector  44 , the display of the signal SG 1  corresponding thereto on the display  10  is also finished. 
     In this manner, the signal SG 1  is displayed on the display  10  at a position corresponding to the direction of the object ahead of the vehicle V, which allows the driver to easily recognize the presence of the object ahead. 
     Processing Example 1 
       FIG.  10    is a flowchart illustrating a processing example of the ECU  35 , showing how the ECU  35  performs processing when the display device  1  performs the operation of Operation Example 1. For example, this flowchart is implemented by the processor of the ECU  35  such as the CPU reading and executing a program stored in the storage device of the ECU  35  such as the semiconductor memory. In addition, for example, this flowchart is repeatedly executed at predetermined intervals while the vehicle V is traveling. Note that in the following description, each step is simply denoted by S 101 , for example. 
     In S 101 , the ECU  35  acquires object detection information. Specifically, the ECU  35  acquires, from the ECU  31 , information that is based on the detection result from the detector  44  as object detection information. Examples of object detection information include the distance between the vehicle V and the detected object, the direction of the object as viewed from the vehicle V, and the relative speed between the vehicle V and the object. Note that the detector  44  can detect a plurality of objects (for example, the vehicles  91  and  92 ), in which case the ECU  35  acquires information on each object. 
     In S 102 , the ECU  35  selects an object. If the information acquired in S 101  includes information on a plurality of objects, the ECU  35  selects one of the plurality of objects. 
     In S 103 , the ECU  35  evaluates the risk of contact between the vehicle V and the selected object. Here, the risk of contact between the vehicle V and the object is expressed by three risk levels of “high”, “medium”, and “low”. However, the risk levels may be subdivided, or may be binary ones such as “at risk” or “not at risk”. Alternatively, the risk of contact may be expressed numerically, for example, as a percentage. 
     A known technique can be used as appropriate as a method of evaluating the risk level; the ECU  35  may evaluate the risk level based on information such as the distance between the vehicle V and the object in the longitudinal direction or the vehicle width direction, the behavior of the object, the relative speed between the vehicle V and the object, and the lane where the vehicle V and the object exist. For example, when the distance between the vehicle V and the object is equal to or greater than a predetermined value, the ECU  35  may rate the risk level lower than when the distance is less than the predetermined value. In addition, for example, for an object having a relatively low speed relative to the vehicle V, e.g. a vehicle traveling ahead of the vehicle V, the ECU  35  may rate the risk level lower than for an object having a relatively high speed relative to the vehicle V, e.g. a pedestrian or a fallen object on a lane. In addition, for example, for an object on the lane on which the vehicle V is traveling, the ECU  35  may rate the risk level higher than for an object outside the lane on which the vehicle V is traveling. That is, the ECU  35  can comprehensively evaluate the risk level based on the various types of information described above. 
     In the present embodiment, for example, the ECU  35  rates the risk level “low” for an object separated from the vehicle V by a predetermined distance or more and/or having a low speed relative to the vehicle V, such as a preceding vehicle. That is, it can be said that an object with a “low” risk level is an object with a low necessity of notification to the driver at the time of evaluation. In addition, for example, the ECU  35  rates the risk level “medium” when the distance between the vehicle V and the selected object is less than the predetermined distance, but the object is not on the lane on which the vehicle V is traveling. In addition, for example, the ECU  35  rates the risk level “high” when the distance between the vehicle V and the selected object is less than the predetermined distance, and the object is on the lane on which the vehicle V is traveling. In addition, for example, the ECU  35  rates the risk level “high” when the distance between the vehicle V and the selected object is less than the predetermined distance, and the object is not on the lane on which the vehicle V is traveling but is moving like a pedestrian and may enter the lane on which the vehicle V is traveling. Note that the predetermined distance here may be a predetermined constant value, or may be a variable value that depends on the speed of the vehicle V and in which the braking distance is considered. 
     In S 104 , the ECU  35  checks whether the risk of contact satisfies a condition, and proceeds to S 105  if the condition is satisfied, otherwise proceeds to S 106 . An example of the condition is that the risk level is “high” or “medium”. For example, in a state like state ST 101 , if the ECU  35  rates the risk level of the vehicle  91  or  92  “medium” in S 103 , the ECU  35  proceeds to S 105 . 
     In S 105 , the ECU  35  executes display control of the display  10 . More specifically, the ECU  35  displays the signal of the position corresponding to the direction of the selected object. The ECU  35  refers to information on the direction of the object selected in S 102  from the information acquired in S 101 . Then, the ECU  35  causes the signal SG 1  to be displayed at the position corresponding to the direction of the selected object. 
     In S 106 , the ECU  35  returns to S 102  if there is an unselected object, otherwise ends the flowchart. Through the above processing by the ECU  35 , the position of the signal displayed on the display  10  of the display device  1  changes as the direction of the vehicles  91  and  92  as viewed from the vehicle V changes as illustrated in  FIGS.  8  to  9   . 
     As described above, according to this processing example, if an object is present ahead of the vehicle V, a signal is displayed on the display  10  at a position corresponding to the direction of the object. Therefore, the driver can intuitively recognize the surrounding situation of the vehicle V. 
     Operation Example 2 
     Next, another operation example of the display device  1  will be described. This operation example is different from Operation Example 1 in that a signal is displayed on the display  10  in a manner that depends on the risk of contact between the vehicle V and the object. Specifically, the display  10  displays the signal in a color that depends on the risk level of contact between the vehicle V and the object. More specifically, in the present embodiment, the display  10  can display an orange signal SG 2  corresponding to an object with a “medium” risk level and a red signal SG 3  corresponding to an object with a “high” risk level. Note that the signal color corresponding to each risk level can be changed as appropriate. 
     In addition, in this operation example, an object around the vehicle V is detected using information received by the V2P communicator  47  in addition to the detector  44 . Furthermore, in this operation example, the risk level is determined by further taking into account the driver&#39;s line of sight monitored by the line-of-sight monitor  45 . 
       FIG.  11    is a diagram illustrating an example situation in which the display device  1  operates.  FIGS.  12  to  13    are forward views from the driver&#39;s seat of the vehicle V in each state in the situation of  FIG.  11   . The illustrated situation shows that the construction vehicles (vehicles  91  and  92 ) are parked in the adjacent lane L 2  adjacent to the traveling lane L 1  on which the vehicle V is traveling, and a pedestrian  93  as an object is crossing the road from between the vehicles  91  and  92 . Note that in  FIGS.  12  to  13   , the direction of the driver&#39;s line of sight identified by the line-of-sight monitor  45  is virtually indicated by a mark  451 . 
     State ST 201  is a state in which the detector  44  has detected the vehicles  91  and  92 , and the ECU  34  has recognized the presence of the pedestrian based on information or the like received by the V2P communicator  47  from the information processing terminal  8  held by the pedestrian  93 . As will be described in detail in (Processing Example 2), in state ST 201 , the risk levels of the vehicles  91  and  92  and the pedestrian  93  are all rated “medium”, and thus the display  10  displays the orange signal SG 2  at the corresponding position. 
     State ST 202  is a state in which the vehicle V has slightly moved forward from state ST 201 . The signal indication position on the display device  1  has changed in accordance with the change in the direction of the vehicles  91  and  92  and the pedestrian  93  as viewed from the vehicle V. As will be described in detail in (Processing Example 2), the risk levels of the vehicles  91  and  92  are recognized as “medium” in state ST 202 , and thus the display  10  displays the signal SG 2  at the corresponding position. On the other hand, the risk level of the pedestrian  93  is recognized as “high”, and thus the display  10  displays the red signal SG 3  at the corresponding position. Note that in this example, the position corresponding to the direction of the vehicles  91  and  92  and the position corresponding to the direction of the pedestrian partially overlap on the display  10 , but the red signal SG 3  indicating a higher risk level is given priority in the overlapping part. 
     The state transitions in states ST 203  to ST 204  are similar to those in states ST 103  to ST 104 . In brief, as the vehicle V approaches the vehicles  91  and  92  and the pedestrian  93 , the direction of the vehicles  91  and  92  and the pedestrian  93  as viewed from the vehicle V shifts, and accordingly the signal indication position on the display  10  changes. 
     Processing Example 2 
       FIG.  14 A  is a flowchart illustrating a processing example of the ECU  35 , showing how the ECU  35  performs processing when the display device  1  performs the operation of Operation Example 2. For example, this flowchart is implemented by the processor of the ECU  35  such as the CPU reading and executing a program stored in the storage device of the ECU  35  such as the semiconductor memory. In addition, for example, this flowchart is repeatedly executed at predetermined intervals while the vehicle V is traveling. Note that S 201  to S 202  and S 206  are similar to S 101  to S 102  and S 106 , respectively, and thus the description thereof is omitted. 
     In S 203 , the ECU  35  evaluates the risk of contact between the vehicle V and the selected object. In this processing example, the ECU  35  evaluates the risk of contact by considering whether the driver is visually recognizing the object in addition to the relative positional relationship and/or speed relationship between the vehicle V and the object.  FIG.  14 B  illustrates a specific processing example of S 203 . 
     In S 231 , the ECU  35  calculates the risk level that is based on the relationship between the vehicle V and the object. More specifically, the ECU  35  calculates the risk level based on the relative positional relationship and/or speed relationship between the vehicle V and the object. Specifically, the ECU  35  can calculate the risk level using the method described in S 103  of  FIG.  10   . For example, in a case where the selected object in state ST 202  is the vehicle  91 , the ECU  35  rates the risk level “high” because the distance between the vehicle V and the vehicle  91  is less than the predetermined distance. In a case where the selected object is the vehicle  92  or the pedestrian  93 , the risk level is rated “high” similarly. 
     In S 232 , the ECU  35  performs a visual recognition determination process. The visual recognition determination process is a process of determining whether the driver is visually recognizing the object. The ECU  35  determines whether the driver is visually recognizing the target object based on the information on the driver&#39;s line of sight acquired from the line-of-sight monitor  45  and the information on the direction of the object acquired from the ECU  31 . For example, in a case where the selected object in state ST 202  is the vehicle  91  or the vehicle  92 , because the mark  451  indicating the direction of the driver&#39;s line of sight overlaps the vehicle  91 , the ECU  35  determines that the vehicle  91  or  92  is being visually recognized. On the other hand, in a case where the selected object is the pedestrian  93 , because the pedestrian  93  is not detected by the detector  44 , it is considered that the pedestrian  93  is located in the blind spot behind the vehicle  91  as viewed from the driver. Therefore, the ECU  35  determines that the driver is not visually recognizing the pedestrian  93  even though the driver&#39;s line of sight may be directed toward the pedestrian  93 . That is, there is a high possibility that the object detected based on the information received by the V2P communicator  47  has not been visually recognized by the driver unless the object has been detected by the detector  44 ; in such a case, therefore, it is determined that the object is not being visually recognized. 
     In S 233 , if it is determined in S 232  that the driver is visually recognizing the object, the ECU  35  proceeds to S 234 , otherwise ends the flowchart. In S 234 , the ECU  35  lowers the risk level calculated in S 231  by one. Conversely, when the selected object is not being visually recognized by the driver, a higher risk level is given than when the selected object is being visually recognized. 
     Returning to  FIG.  14 A , in S 204 , the ECU  35  proceeds to S 205  if the evaluation result in S 203  is “high”, proceeds to S 207  if the evaluation result is “medium”, and proceeds to S 206  if the evaluation result is “low”. 
     In S 205 , the ECU  35  displays the signal of the position corresponding to the selected object in red. The ECU  35  refers to information on the direction of the object selected in S 202  from the information acquired in S 201 . Then, the ECU  35  causes the light emitter  103  at the position corresponding to the direction of the selected object to emit light in red. 
     In S 207 , the ECU  35  displays the signal of the position corresponding to the selected object in orange. The ECU  35  refers to information on the direction of the object selected in S 202  from the information acquired in S 201 . Then, the ECU  35  causes the light emitter  103  at the position corresponding to the direction of the selected object to emit light in orange. 
     According to this processing example, a signal is displayed on the display  10  in a manner that depends on the risk level of the object, which can help the driver more appropriately grasp the surrounding situation. In addition, the risk level of an object which is not being visually recognized by the driver is rated relatively high, which can make the driver effectively recognize the presence of the object which is not being recognized by the driver. 
     Note that in this processing example, the risk level is lowered by one when the driver is visually recognizing the object, but it is also possible to adopt a configuration in which no signal is displayed when the driver is visually recognizing the object. For example, if it is determined in S 232  that the driver is visually recognizing the object, the risk level may be lowered to “low”, at which signal indication is not provided. This makes it possible to display signals exclusively for an object which is not being visually recognized by the driver, so that the driver can be effectively notified of an object with a high risk of contact while being less annoyed with signals. 
     Operation Example 3 
     Next, still another operation example of the display device  1  will be described. This operation example is different from Operation Example 2 in the method of evaluating the risk of contact. Specifically, in Operation Example 2, the risk level is evaluated such that an object which is not being recognized by the driver is given a relatively high risk level. As a result, the manner of signal indication on the display  10  varies depending on whether the driver is visually recognizing the object or not. On the other hand, in this operation example, even when the driver is not visually recognizing the object, the signal is displayed on the display  10  in the same manner as when the driver is visually recognizing the object for a predetermined time after the last visual recognition. Note that the predetermined time here can be set as appropriate; for example, may be set to a value between 3 and 10 seconds. 
       FIG.  15    is a diagram illustrating an example situation in which the display device  1  operates.  FIGS.  16  to  17    are forward views from the driver&#39;s seat of the vehicle V in each state in the situation of  FIG.  15   . The illustrated situation shows that the vehicle V is about to turn right at the intersection but is waiting for a pedestrian and the like to cross at the crosswalk. Specifically, the situation shows that after a pedestrian  94  as an object detected by the detector  44  crosses in front of the vehicle V, a bicycle  95  as an object detected by the detector  44  crosses in front of the vehicle V. 
     State ST 301  is a state in which the pedestrian  94  has started to cross in front of the vehicle V. At this time, the driver&#39;s line of sight is directed to the pedestrian  94  as indicated by the mark  451 , and it is considered that the driver is recognizing the pedestrian  94 . Therefore, the ECU  35  rates the risk level of the pedestrian  94  “medium” and displays the orange signal SG 2  at the corresponding position on the display  10 . 
     State ST 302  is a state in which the pedestrian  94  has almost finished crossing in front of the vehicle V, and the bicycle  95  has started to cross in front of the vehicle V. At this time, the driver&#39;s line of sight is directed to the pedestrian  94  as indicated by the mark  451 , and it is considered that the driver is recognizing the pedestrian  94  but is not recognizing the bicycle  95 . Therefore, the ECU  35  rates the risk level of the pedestrian  94  “medium” and displays the orange signal SG 2  at the corresponding position on the display  10 , while the ECU  35  rates the risk level of the bicycle  95  “high” and displays the red signal SG 3  at the corresponding position on the display  10 . 
     State ST 303  is a state in which the pedestrian  94  has finished crossing in front of the vehicle V, and the bicycle  95  keeps crossing in front of the vehicle V. Although the pedestrian  94  is not illustrated here, the pedestrian  94  is present in the detection angle range DA1 of the detector  44 , and thus the signal corresponding to the pedestrian  94  is displayed on the display  10 . In addition, the driver&#39;s line of sight is not directed to the pedestrian  94  as indicated by the mark  451 , but the predetermined time has not elapsed since the driver&#39;s last visual recognition of the pedestrian  94 ; therefore, the ECU  35  rates the risk level of the pedestrian  94  “medium” and displays the orange signal SG 2 . Meanwhile, the driver has not yet visually recognized the bicycle  95 , and thus the ECU  35  rates the risk level of the bicycle  95  “high” and displays the red signal SG 3  at the corresponding position on the display  10 . 
     State ST 304  is a state in which the bicycle  95  has almost finished crossing in front of the vehicle V. Because the pedestrian  94  is out of the detection angle range DA1 of the detector  44 , no signal is displayed on the display  10  corresponding to the pedestrian  94 . In addition, the driver&#39;s line of sight is directed to the bicycle  95  as indicated by the mark  451 , and thus the ECU  35  rates the risk level of the bicycle  95  “medium” and displays the orange signal SG 2  at the corresponding position on the display  10 . 
     According to this operation example, it is possible to prevent the signal indication on the display  10  from being frequently switched due to, for example, a change in the color of the signal or disappearance of the signal soon after the driver&#39;s removal of the line of sight from the object. Therefore, it is possible to prevent signal flickering to make the driver feel less annoyed. In addition, because the risk level of an object which has once been visually recognized is unlikely to rise for the predetermined time, it is possible to effectively notify the driver of an object which is not being visually recognized by the driver and has a higher risk of contact. 
     Processing Example 3 
       FIG.  18    is a flowchart illustrating a processing example of the ECU  35 , showing a specific processing example of S 203  in  FIG.  14 A . That is, when the display device  1  performs the operation of Operation Example 3, the ECU  35  executes the process of  FIG.  14 A , but the specific procedure for S 203  is different from that in the case of performing the operation of Operation Example 2. 
     S 331  and S 332  are steps similar to S 231  and S 232 , respectively. For example, in a case where the selected object in state ST 302  is the bicycle  95 , the ECU  35  rates the risk level “high” because the distance between the vehicle V and the bicycle  95  is less than the predetermined distance and the bicycle  95  is moving. 
     In S 333 , if it is determined in S 332  that the driver is visually recognizing the object, the ECU  35  proceeds to S 334 , otherwise proceeds to S 335 . In S 335 , the ECU  35  checks whether the predetermined time has elapsed since the driver&#39;s last visual recognition of the object, and if the predetermined time has elapsed, ends the flowchart, otherwise proceeds to S 334 . Because this flowchart is repeatedly executed at predetermined intervals, the ECU  35  can acquire the elapsed time from the driver&#39;s last visual recognition of the object using the determination results in previous control cycles. In S 334 , the ECU  35  lowers the risk level calculated in S 331  by one. 
     Through steps S 333  to S 335 , the ECU  35  lowers the risk level calculated in step S 331  by one if the driver is visually recognizing the object and if the driver is not currently visually recognizing the object but the predetermined time has not elapsed since the last visual recognition. That is, until the predetermined time elapses after the driver&#39;s last visual recognition of the object, the signal is displayed in the same manner as when the driver is visually recognizing the object. 
     If the driver has once visually recognized the object, the risk of contact is considered to be low. Therefore, by displaying the signal in the same manner as when the driver is visually recognizing the object for the predetermined time after the driver&#39;s removal of the line of sight, it is possible to prevent the signal indication from being frequently switched, and to prevent the driver from feeling annoyed more effectively. 
     Other Embodiments 
     It is also possible to adopt a configuration in which the signal indication by the display device  1  is linked to the tension of the seat belt for the driver&#39;s seat.  FIG.  19    is a schematic diagram illustrating the configuration of an adjuster for the tension of the seat belt for the driver&#39;s seat according to an embodiment. 
     The vehicle V includes an adjuster  49  that adjusts the tension of a seat belt  48  worn by the driver. The adjuster  49  increases the tension of the seat belt  48  by pulling the seat belt  48  in the direction of the arrow in the drawing with the rotational driving force of a motor or the like. The adjuster  49  also reduces the tension of the seat belt  48  by rotating the motor or the like in the direction opposite to the direction in which the tension of the seat belt  48  is increased. The driving of the adjuster  49  can be controlled by an ECU included in the control unit  3 . 
     In such a configuration, the manner of signal indication on the display device  1  and the tension of the seat belt  48  adjusted by the adjuster  49  may be linked. For example, the adjuster  49  may be configured not to generate tension on the seat belt  48  when no signal is displayed on the display  10 , and to generate tension on the seat belt  48  when a signal is displayed on the display  10 . In addition, for example, in a case where the manner of signal indication on the display  10  depends on the risk level of the object, the tension of the seat belt  48  may be adjusted by the adjuster  49  such that the seat belt  48  has a higher tension at the risk level “high” than at the risk level “medium”. Alternatively, the adjuster  49  may generate tension on the seat belt  48  when a signal is displayed on the display  10  and the driver is not visually recognizing the target object. This allows the driver to more easily grasp the risk of contact with the object. 
     The above embodiment has described the configuration in which signals are displayed in different colors as an example of changing the manner of signal indication according to the risk level; however, the manner of signal indication may be changed using different levels of signal brightness, different patterns of blinking, or the like. 
     In addition, the display  10  may have a diffusion plate that diffuses light emitted by the plurality of light emitters  103 . The provision of the diffusion plate is effective in preventing signal flickering especially when the size of the light emitters  103  is small, for example. 
     In addition, in the signal indication by the display  10 , the width of a signal may be a fixed value or may vary according to the width of the detection angle of the object. Setting the width of a signal to a fixed value (for example, the value corresponding to one light emitter  103 ) is advantageous in that the driver can readily recognize a plurality of objects that exist in substantially the same direction. In addition, varying the width of a signal according to the detection angle of the object is advantageous in that the driver can more accurately grasp the presence of the object. In addition, in a case where a signal is displayed with some width, the color of the signal may differ between the central part and the outer part. 
     In addition, in the above embodiment, the display  10  does not display a signal at a position corresponding to a direction in which no object is detected or a direction in which an object with a low risk level is present, but signals may also be displayed at these positions. For example, the display  10  may display a red or orange signal at a position corresponding to a direction in which an object with a high risk level is present, and may display a green or light blue signal at a position corresponding to a direction in which no object is detected or a direction in which an object with a low risk level is present. 
     In addition, the shape of the display  10  is not limited to the arc shape, and other shapes can be adopted. For example, a part of the base portion  104  may be formed linearly in plan view, or a plurality of linear parts may be combined to form the base portion  104 . That is, the display  10  only needs to include a part recessed forward in the vehicle longitudinal direction in plan view. 
     In addition, for example, in a case where the detector  44  (camera) is installed at the center in the vehicle width direction of the vehicle, because the display  10  needs to be installed in front of the driver, the position of the signal (LED lighting) displayed corresponding to the detected object may appear to deviate from the position of the object as the object approaches the vehicle. For example, in the case of a right-hand drive vehicle, an object in front of the detector  44  may be seen by the driver to be located diagonally forward left. In order to correct this, calculation may be performed to correct the position of the object detected by the detector  44  to the position of the object as viewed from the driver, and the signal indication position may be converted to match the position of the object as viewed from the driver. 
     Summary of Embodiments 
     The above embodiments disclose at least the following vehicle. 
     1. A vehicle (for example, V) comprising: 
     a detector (for example, 44) configured to detect an object at least ahead of the vehicle; and 
     a display (for example, 10) provided on an instrument panel (for example, 2) of the vehicle and configured to display a signal at a position corresponding to a direction of the object detected by the detector, wherein the display includes a part recessed forward in a vehicle longitudinal direction in plan view. 
     According to this embodiment, it is possible to provide the surrounding situation of the vehicle to the driver in an easy-to-recognize manner. 
     2. The vehicle according to claim  1 , wherein the display is provided above a meter visor (for example, 22) included in the instrument panel. 
     According to this embodiment, the display is located where the display is likely to stay in the driver&#39;s field of vision during driving, so that the driver can easily check the indication on the display during driving. In addition, the signal can enter the lower part of the driver&#39;s view without blocking the view. 
     3. The vehicle according to claim  1 , wherein 
     the display includes a part shaped like an arc, and 
     a central angle (for example, CA1) of the arc (for example, AR1) formed by the display corresponds to a detection angle range (for example, DA1) of the detector. 
     According to this embodiment, the direction of the object as viewed from the vehicle can be more accurately reflected in the signal indication on the display. 
     4. The vehicle according to claim  3 , wherein 
     the display includes a plurality of light emitting elements (for example, 103) provided along a circumferential direction of the arc, and 
     an angle (for example, θv1) formed by two virtual line segments (for example, VL1, VL2) each connecting a center of the arc and one of two adjacent light emitting elements of the plurality of light emitting elements is equal to or larger than a detection error angle in the detector. 
     According to this embodiment, it is possible to prevent the signal indication from flickering due to the influence of detection error. 
     5. According to the above embodiments, 5. The vehicle according to claim  3 , wherein 
     an angle (for example, θv2) formed by two virtual line segments (for example, VL3, VL4) each connecting one of opposite ends (for example, 1042, 1043) of the display in a vehicle width direction and an eye point (for example, EP) set in the vehicle is in a range of ⅕ of the detection angle range to the detection angle range. 
     According to this embodiment, it is possible to appropriately associate the signal indication position on the display with the direction of the object ahead. 
     6. The vehicle according to claim  1 , further comprising: 
     a line-of-sight monitor (for example, 45) configured to monitor a driver&#39;s line of sight; and 
     a determination unit (for example, 35, S 232 ) configured to determine whether the driver is visually recognizing the object detected by the detector based on a monitoring result from the line-of-sight monitor, wherein the display displays the signal in different manners depending on whether it is determined by the determination unit that the driver is visually recognizing the object or it is determined by the determination unit that the driver is not visually recognizing the object (for example, S 233 -S 234 ). 
     According to this embodiment, the driver can recognize the presence of an object which is not being visually recognized by the driver, and thus can more accurately grasp the situation surrounding the vehicle. 
     7. The vehicle according to claim  6 , wherein 
     while it is determined by the determination unit that the driver is not visually recognizing the object, the display displays the signal in a same manner as when the driver is visually recognizing the object until a predetermined time elapses after a last determination by the determination unit that the driver is visually recognizing the object (for example, S 333 -S 335 ). 
     According to this embodiment, it is possible to prevent the signal indication from being frequently switched to make the driver feel less annoyed. 
     8. The vehicle according to claim  1 , further comprising 
     an evaluation unit (for example, S 203 ) configured to evaluate a risk of contact between the vehicle and the object detected by the detector, wherein 
     the display displays the signal in a manner that depends on the risk of contact evaluated by the evaluation unit (for example, S 204 - 205 ). 
     According to this embodiment, the signal is displayed in a manner that depends on the risk of contact, which allows the driver to more accurately grasp the situation surrounding the vehicle. 
     9. The vehicle according to claim  8 , wherein 
     the display displays the signal with light of a color that depends on the risk of contact (for example, S 204 -S 205 ). 
     According to this embodiment, it is possible to more intuitively grasp the risk of contact with the object. In addition, it is possible to notify the driver of the risk of contact with a simple structure. 
     10. The vehicle according to claim  8 , wherein 
     the display displays the signal when the risk of contact satisfies a predetermined condition (for example, S 104 ). 
     According to this embodiment, no signal is displayed for an object with a low risk of contact, which allows the driver to be notified of only necessary information. 
     11. The vehicle according to claim  1 , further comprising 
     an adjuster (for example, 49) configured to adjust tension of a seat belt (for example, 48) worn by a driver, wherein 
     the tension of the seat belt adjusted by the adjuster is linked to a manner in which the signal is displayed by the display. 
     According to this embodiment, the driver can more readily recognize the situation surrounding the vehicle. 
     The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.