Patent Publication Number: US-2019193634-A1

Title: Vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 USC 119 from Japanese Patent Application No. 2017-252266 filed on Dec. 27, 2017, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a vehicle. 
     Related Art 
     Japanese Patent Application Laid-Open (JP-A) No. 2016-147528 discloses an image display device including: a center display which is a transparent type display; and a left display and a right display, which are positionally switched between a first position behind the center display and a second position different from the first position. At the first position, the left display and the right display each display a second image associated with a first image displayed on the center display. 
     In the actual operations of a vehicle, for example, depending on the weather and the like, there are cases where it is difficult to drive the vehicle due to the difficulty in visually recognizing the width positions of the road. The technology of JP-A No. 2016-147528 is not configured in such a manner to facilitate visual recognition of the width positions of a road; therefore, there is room for improvement in terms of making driving easier. 
     SUMMARY 
     The present disclosure makes driving easier in a case in which it is difficult to visually recognize the width positions of a road. 
     In a first aspect of the present disclosure, a vehicle includes (i) a vehicle main body, (ii) a road width information acquisition unit that acquires road width information relating to the width of a road surrounding the vehicle main body, and (iii) a display unit that displays width positions of the road based on the road width information acquired by the road width information acquisition unit, the display unit being arranged in the compartment of the vehicle main body. 
     In the vehicle according to the first aspect, the road width information acquisition unit acquires road width information relating to a width of the road surrounding the vehicle main body. Based on this road width information, the display unit displays the width positions of the road. The occupant can obtain a knowledge of the width positions of the road by visually recognizing the width positions of the road displayed by the display unit. Even when it is difficult to visually recognize the width positions of the road, the occupant may easily drive the vehicle by knowing the width positions of the road. 
     In a second aspect, the display unit according to the first aspect includes a projection member which projects an image on a window of the vehicle main body. 
     In the second aspect, since an image indicating the width positions of the road is projected and displayed on the window by the projection member, it is easy to visually recognize the width positions of the road. 
     In a third aspect, the projection member according to the second aspect projects the width positions on the window with lines. 
     In the third aspect, since the width positions of the road are displayed with lines, the width positions (boundaries) of the road can be clearly indicated. 
     In a fourth aspect, the vehicle according to any one of the first to the third aspects includes a visibility condition sensor which detects a visibility condition of the width of the road surrounding the vehicle main body, and the display unit displays the width positions in accordance with the visibility condition detected by the visibility condition sensor. 
     In the fourth aspect, the display unit displays the width positions of the road in accordance with the visibility condition of the width of the road surrounding the vehicle main body that is detected by the visibility condition sensor. For example, even when the width positions of the road are not visually recognizable, the width positions of the road can be appropriately displayed. 
     In a fifth aspect, the vehicle according to any one of the first to the fourth aspects includes an input unit which receives an input of a display request for the width positions from an occupant, and the display Unit displays the width positions in the presence of the input of the display request. 
     In the fifth aspect, the display unit displays the width positions of the road in the presence of an input of a display request; however, the display unit does not display the width positions in the absence of such an input and is thereby prevented from having excessive display contents. For example, when the display unit does not display the width positions, it can display other information, in place of the width positions. 
     In a sixth aspect, in the vehicle according to any one of the first to the fifth aspects, the road width information acquisition unit includes a vehicle location information acquisition unit that detects location information of the vehicle, and the display unit acquires the width positions from an external database and displays the width positions based on the vehicle location acquired by the vehicle location information acquisition unit. 
     The display unit acquires the width positions of the road from an external database and displays the width positions; therefore, for example, even when the width positions of the road are not recognizable by image capturing or the like, the width positions of the road can be displayed. 
     The road width information acquisition unit includes the vehicle location information acquisition unit and is thus capable of acquiring the width positions of the road from an external database in accordance with the location of the vehicle. 
     In a seventh aspect, in the vehicle according to any one of the first to the sixth aspects, the road width information acquisition unit includes an imaging camera which captures an image of the surroundings of the vehicle and thereby acquires the width positions. 
     In the seventh aspect, since an image of the road is captured by the imaging camera, the width positions can be displayed more accurately. 
     In an eighth aspect, the display unit according to the seventh aspect corrects the width positions of the road based on the image captured by the imaging camera and displays the thus corrected width positions. 
     In the eighth aspect, since the display unit corrects and then displays the width positions of the road, the width positions can be displayed more accurately. 
     The ninth aspect of the present disclosure is a method for displaying road width position, the method comprising (i) acquiring road width information relating to a width of a road surrounding a vehicle main body, and (ii) displaying width positions of the road based on the acquired road width information, at a display unit disposed in a compartment of the vehicle main body. 
     The tenth aspect of the present disclosure is a non-transitory computer readable medium storing a program that causes a computer to execute a process for displaying road width position, the process comprising (i) acquiring road width information relating to a width of a road surrounding a vehicle main body, and (ii) displaying width positions of the road based on the acquired road width information, at a display unit disposed in a compartment of the vehicle main body. 
     According to the present disclosure, driving can be made easier even when it is difficult to visually recognize the width positions of a road. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein: 
         FIG. 1  is a side view illustrating a vehicle of a first embodiment; 
         FIG. 2  is a view taken from the inside of the compartment toward the front in the vehicle of the first embodiment; 
         FIG. 3  is a drawing that illustrates the position of the windshield in the vehicle of the first embodiment; 
         FIG. 4  is a block diagram of the vehicle of the first embodiment; 
         FIG. 5  is a drawing that illustrates the state of division lines viewed from the windshield toward the front in the vehicle of the first embodiment; 
         FIG. 6  is a flow chart of a road width position information display process in the vehicle of the first embodiment; 
         FIG. 7  is a drawing that illustrates one example of an image displayed on a display panel in the vehicle of the first embodiment; 
         FIG. 8  is a drawing that illustrates one example of an image projected from the projection member in the vehicle of the first embodiment; 
         FIG. 9  is a drawing that illustrates the width between projected division lines and that between actual lines; 
         FIG. 10  is a drawing that illustrates one example of an image projected from the projection member in the vehicle of the first embodiment, the example being different from the one illustrated in  FIG. 8 ; and 
         FIG. 11  is a block diagram illustrating a hardware configuration of a control unit of a control device. 
     
    
    
     DETAILED DESCRIPTION 
     A vehicle  102  according to the first embodiment of the present disclosure will now be described in detail referring to the figures. The simple terms “front side” and “rear side” used herein mean the front side and the rear side along the vehicle anteroposterior direction, respectively, and the terms “upper side” and “lower side” mean the upper side and the lower side along the vehicle vertical direction, respectively. 
     As illustrated in  FIGS. 1 and 2 , the vehicle  102  includes a vehicle main body  104 , inside of which is a vehicle compartment  106 . A dashboard  108  is arranged on the front side of the vehicle compartment  106 , and a windshield  112  is arranged above the dashboard  108 . 
     A display panel  116  is arranged on the dashboard  108 . In this embodiment, the display panel  116  is arranged at a central position in the vehicle widthwise direction on the dashboard  108 . 
     The display panel  116  doubles as an input device  118  and also functions as an input panel which receives an input made by an occupant&#39;s touch operation. As the input device  118 , an input display (e.g., a touch panel) or various input switches (e.g., push buttons and slide switches) may be arranged separately from the display panel  116 . Further, for example, a microphone which receives a voice input from an occupant, or a sensor which detects a motion of an occupant (movement of an arm or a fingertip) can also be used as the input device  118 . For example, by inputting the place where the vehicle main body  104  is heading to (occupant&#39;s destination) using the input device  118  to display information on a route to the destination on the display panel  116 , the display panel  116  is allowed to function as a part of a car navigation system. The information on the route to the destination may be presented by a device other than the display panel  116 , for example, by voice from a speaker (not illustrated). 
     As illustrated in  FIG. 3 , a projection member  122  is arranged inside the dashboard  108 . The projection member  122  is one example of the display unit of the present disclosure. 
     The projection member  122  projects a projected image  126  at a prescribed position on the windshield  112  through a projection window  124  of the dashboard  108 . This projected image  126  is projected in such a manner to form a virtual image  128  further on the front side than the windshield  112  when viewed from an occupant PG. The occupant PG can visually recognize the projected image  126  in a superimposed manner with the sight outside the vehicle created by the light transmitting through the windshield  112 . In other words, the projection member  122  of this embodiment is a head-up display. 
     As illustrated in  FIG. 4 , a control device  130  is connected to the display panel  116  and the projection member  122 . The control device  130  includes a first output unit  132  and a second output unit  134 . The first output unit  132  and the second output unit  134  each output a prescribed image to the display panel  116  and the projection member  122 , respectively. 
     The control device  130  also includes a memory unit  136  and a control unit  138 . In the memory unit  136 , for example, a road width position display program for executing the below-described “road width position display process” has been stored in advance. Further, the input device  118  is connected to the control device  130 , and it is configured such that information inputted to the input device  118  is transmitted to the control device  130 . 
       FIG. 11  shows a block diagram of a hardware configuration of the control unit  138 . The control unit  138  includes a Central Processing Unit (CPU)  202 , a Read Only Memory (ROM)  204 , and a Random Access Memory (RAM)  206 . The control unit  138  is connected to the memory unit  136 . These components are connected in a mutual communication manner via a bus  208 . 
     The CPU  202  is formed as a central processing unit so as to execute various programs and to control each portion. That is, the CPU  202  reads a program from the ROM  204  or the memory unit  136  and executes the program using the RAM  206  as a working area. The CPU  202  performs the control of each unit included in the vehicle main body  104  and various calculations in accordance with the program stored in the ROM  204  or the memory unit  136 . 
     The ROM  204  stores various programs and various data. Note that programs and data, or portions thereof, which are described to be stored in the memory unit  136  throughout the present disclosure, can be stored at the ROM  204  instead of the memory unit  136 . The RAM  206  stores the programs or the data temporarily as a working area. 
     For convenience of explanation, hereinafter, performing various functions of the vehicle main body  104  by the ROM  204  of the control unit  138  executing the road width position information display program stored in the memory unit  136  is described as that the control unit  138  controls the vehicle main body  104 . 
     To an I/O (Input/Output) port  156  of the control device  130 , in addition to the input device  118 , a location receiving device  144 , an imaging camera  148  and a wireless communication device  146  are also connected. The control unit  138 , in accordance with the various information inputted to the control device  130 , processes image information to be outputted from each of the first output unit  132  and the second output unit  134  to the display panel  116  and the projection member  122 . 
     The location receiving device  144  receives current location information of the vehicle  102  from, for example, a global positioning system (GPS). The location receiving device  144 , which is one example of the location information acquisition unit of the present disclosure, is controlled by the control unit  138  of the control device  130 . The wireless communication device  146 , for example, wirelessly communicates with an external server via an inter-net connection or the like to transmit and receive information. The wireless communication device  146  of this embodiment is capable of acquiring information on the road width positions based on the current location of the vehicle  102 . 
     For a road having division lines, the term “width positions” refers to the boundary positions of the division lines on each widthwise side of the lane on which the vehicle  102  is travelling. For example, as illustrated in  FIG. 5 , on a two-lane road RD- 1 , the positions of a roadway center line LC and a roadway edge line LS each correspond to the “width positions”. 
     Meanwhile, the “width positions” on a road having no division line can be set as the positions of the boundaries along the road widthwise direction between the area where the vehicle can substantially travel and the areas where the vehicle cannot travel. For example, in the case of a road having a shoulder, a curbstone, a gutter, a sidewalk, a slope and/or the like on each side, such shoulder, curbstone, gutter, sidewalk, slope and the like are the areas where the vehicle cannot travel. 
     As illustrated in  FIG. 1 , the imaging camera  148  is attached to the vehicle main body  104  in such a manner that it can take images ahead of the vehicle. In this embodiment, as one example of an imaging device, a camera which is capable of capturing images of a prescribed area wider than the road width (lane width in the case of a multi-lane road) as still pictures at prescribed time intervals or as a video is used. The imaging camera  148  transmits the thus obtained information of the captured images ahead of the vehicle main body  104  to the control device  130 . The wireless communication device  146  and the imaging camera  148  are examples of the road width information acquisition unit of the present disclosure. The control unit  138  of the control device  130  reads out a prescribed program stored in the memory unit  136  and executes the control of the road width information acquisition unit. 
     The imaging device is not restricted to a camera that takes images of visible light and may be, for example, a camera that takes images using infrared or ultraviolet radiation. These cameras are also examples of the imaging device and, at the same time, examples of the visibility condition sensor of the present disclosure. The control unit  138  of the control device  130  reads out a prescribed program stored in the memory unit  136  and executes the control of the visibility condition sensor. 
     The term “visibility condition” refers to a state whether or not the occupant PG can visually recognize the width positions of a road surrounding the vehicle main body  104 . Accordingly, examples of the visibility condition sensor include those sensors that are configured to detect the shape of a road surface RS and acquire information on the road width positions by irradiating ultrasonic waves to the road surface RS or by irradiating a laser to the road surface RS using a laser interferometer. Any of such visibility condition sensors can be used to determine the visibility condition of the width positions (actual division lines RL) of the road surrounding the vehicle main body  104 , i.e., information used for judging whether or not the occupant PG can visually recognize the width positions of the road. 
     Even when the occupant PG cannot visually recognize the width positions of the road, there are cases where the width positions of the road can be recognized as a captured image by adjusting the light exposure or taking an image through an appropriate filter in the image capturing performed by the imaging camera  148 . Similarly, in some cases, the width positions of the road can be recognized as a captured image by adopting a configuration that takes an image using infrared or ultraviolet radiation or a configuration that detects the shape of the road surface using a laser interferometer. 
     Next, a method of displaying the “width positions” of a road ahead of the vehicle  102  of this embodiment will be described. In the vehicle  102  of this embodiment, the control unit  138  of the control device  130  reads out a prescribed program stored in the memory unit  136  and executes a “road width position display process” for displaying a prescribed display content using the display panel  116  and the projection member  122  in accordance with the flow illustrated in  FIG. 6 . In the execution of this “road width position display process”, as illustrated in  FIG. 7 , the control device  130  displays, on the display panel  116 , a selection screen P 11  which asks whether or not to display the “width positions” of the road. Then, when it is judged that an input for not displaying the “width positions” of the road has been made, the “road width position display process” is not executed. In other words, the “road width position display process” is executed when it is judged that an input for displaying the width positions of the road has been made. 
     First, in the step S 12 , the control device  130  judges the visibility condition ahead of the vehicle  102 , i.e., whether or not the occupant PG can visually recognize the width positions of the road. Specifically, based on an image ahead of the vehicle that is taken by the imaging camera  148  (hereinafter, this image is referred to as “captured image”), it is judged whether or not the division lines of the road (e.g., white solid lines, white dotted lines and yellow solid lines, which are hereinafter referred to as “actual division lines RL”; see  FIG. 5 ) can be distinguished from the road surface RS excluding the actual division lines RL. For example, in the case of snowfall on the road surface, the actual division lines RL are sometimes not visually recognizable. Further, when rainwater remains on the road surface RS or in the event of dense fog, heavy rain or the like, it may be difficult to visually recognize the actual division lines RL. Whether or not the actual division lines RL are actually visually recognizable can be determined by comparing the hue and the brightness between the actual division lines RL and the road surface RS excluding the actual division lines RL. 
     In the step S 12 , if the width positions are judged to be visually recognizable, the control device  130  terminates the “road width position display process”. 
     On the other hand, when the width positions are judged to be not visually recognizable in the step S 12 , the process proceeds to the step S 14 . In the step S 14 , the control device  130  acquires location information of the vehicle main body  104  from the location receiving device  144 . Further, in the step S 16 , the control device  130  acquires information on the width positions of the road. Specifically, for example, the control device  130  accesses an external server via the wireless communication device  146  and acquires the information on the “width positions” from an image of the road at the current location of the vehicle main body  104  (this image is hereinafter referred to as “acquired image”). When the road has actual division lines RL in an aerial photograph of the road that is stored in the external server, the information on the “width positions” can be acquired as the positions of the actual division lines RL. Meanwhile, when the road has no actual division line Rh or the road has actual division lines RL but they are unclear on the aerial photograph, for example, the information on the “width positions” can be estimated from the positions of a curbstone, a guardrail, a shoulder, a sidewalk, a slope and the like of the road. Further, the information on the “width positions” of the road may be recorded in advance in the memory unit  136  of the control device  130  while the “width positions” of the road are recognizable, and this information may be extracted. In the following, a case where the information on the “width positions” of the actual division lines RL has been obtained from the “acquired image” is described as an example. 
     Subsequently, the control device  130  proceeds to the step S 18 . In the step S 18 , the control device  130  executes “alignment” in which the positions of division lines projected from the projection member  122  (hereinafter, these division lines are referred to as “projected division lines PL”; see  FIG. 8 ) are corrected such that they are aligned with the actual position of the road. In other words, the captured image obtained by the imaging camera  148  and the acquired image obtained from the location receiving device  144  are compared, and the positions at which the projected division lines PL should be projected are determined based on the captured image. The positions of the projected division lines PL are corrected based on the captured image; therefore, displacement of the projected division lines PL. 
     The control device  130  then proceeds to the step S 20 . In the step S 20 , the control device  130  projects the projected division lines PL at the thus determined respective positions from the projection member  122 . As illustrated in  FIG. 8 , the projected division lines PL are projected on the windshield  112 , allowing the occupant PG to visually recognize the projected division lines PL. In other words, even in a situation where the occupant PG cannot visually recognize the actual division lines RL or has difficulty in visually recognizing the actual division lines RL, the occupant PG can easily visually recognize the projected division lines PL to drive the vehicle  102 . 
     Thereafter, the process returns back to the step S 12 . In the step S 12 , the control device  130  again judges the visibility condition ahead of the vehicle  102 , i.e., whether or not the occupant PG can visually recognize the width positions of the road. 
     It is noted here that the projected division hues PL indicating the width positions of the road can also be displayed on the display panel  116 . For example, the captured image of the road that is taken by the imaging camera  148  may be displayed on the display panel  116 , and the width positions of the road (projected division lines PL) may be superimposed on the captured image on the display panel  116 . In contrast, in the above-described embodiment, since the width positions of the road (projected division lines PL) are projected and displayed on the windshield  112 , the width positions of the road are displayed over the actual road; therefore, it is easy to visually recognize the width positions of the road. 
     In this manner, the window on which the width positions of the road are displayed is not restricted to the windshield  112 . For example, a projection member which projects images on a rear window or a door glass may be arranged inside the vehicle compartment  106  so as to display the width positions of the road on the rear window or the door glass. 
     Particularly, in the above-described embodiment, since the positions of the projected division lines PL are corrected based on the captured image, displacement of the projected division lines PL is inhibited, so that the projected division lines PL can be displayed at more accurate positions (positions closer to those of the actual division lines RL). 
     In this embodiment, as illustrated in  FIG. 9 , in the projected division lines PL, a width W 2  visually recognized by the occupant PG from the inside of the vehicle compartment  106  is set to be wider than a width W 1  between the actual division lines RL (a width that is also visually recognized by the occupant PG from the inside of the vehicle compartment  106 ). Thus, even if the positions of the projected division lines PL are slightly displaced in the widthwise direction with respect to the positions of the actual division lines RL, a state where the projected division lines PL exist within an area containing actual division lines RL can be realized. 
     Moreover, in the above-described embodiment, an image of the surroundings of the vehicle  102  is captured by the imaging camera  148 , and the positions at which the projected division lines PL should be projected are determined using the thus captured image. As compared to a configuration in which no image of the surroundings of the vehicle  102  is taken by the imaging camera  148 , the positions of the projected division lines PL can be determined more accurately. 
     In addition, since an image of the outside of the vehicle  102  is captured by the imaging camera  148 , it is possible to judge whether or not the occupant can visually recognize the width positions of the road and to perform a process of displaying the projected division lines PL when the occupant cannot visually recognize the width positions of the road. When the actual division lines RL are visually recognizable, the power consumption of the projection member  122  can be reduced by not displaying the projected division lines PL. 
     Furthermore, in the above-described embodiment, since the input device  118  is provided, the occupant can select whether or not to display the width positions of the road. When the occupant does not wish to display the width positions of the road, the power consumption of the projection member  122  can be reduced by not displaying the width positions of the road. In addition, by not displaying the width positions of the road, it is possible to prevent the contents to be displayed on the windshield  112  from being excessive and thus, for example, other information can also be displayed in place of the width positions of the road. 
     In the above-described embodiment, the width positions of the road can be recognized based on an image captured by the imaging camera  148 ; however, depending on the situation, it may be difficult to recognize the width positions of the road. Still, even when the width positions of the road cannot be recognized based on an image captured by the imaging camera  148 , since the information on the width positions of the road is acquired from an external database, the width positions of the road can be displayed by projecting the division lines PL using the projection member  122 . 
     It is noted here that, although a case of displaying the width positions of a road with projected division lines PL was described above as one example, the display of the width positions of a road is not restricted to such a case of using lines. For example, as illustrated in  FIG. 10 , the entirety of a road lane on which the vehicle  102  can travel may be displayed as a projected surface PS, Further, a virtual guardrail may be displayed at a width position of the road surface RS. By displaying the width positions of a road with projected division lines PL, i.e., lines, the width positions of the road are made clear and thus easily visually recognized. 
     Further, the road width position display process performed by the CPU  202  reading the program in the embodiment described above may be performed various processors other than a CPU. In this case, an example of the processor includes a Programmable Logic Device (PLD), the circuit configuration of which can be changed after manufacturing the device, such as a Field-Programmable Gate Array (FPGA), and a specific electric circuit formed as a processor having a circuit configuration specifically designed for performing specific processing such as an Application Specific Integrated Circuit (ASIC). Further, the location-related information display processing may be performed by one of the various processors, or a combination of two or more of similar processors or different processors (for example, a combination of a plurality of the FPGAs, a combination of the CPU and the FPGA, or the like). Further, a hardware configuration of the various processors is specifically formed as an electric circuit combining circuit elements such as semiconductor element. 
     Further, in the embodiments described above, the location-related information display program is stored in the memory unit  136  or the ROM  204 , however it is not limited to this. The program may be provided by a storage medium such as a Compact Disk Read Only Memory (CD-ROM), a Digital Versatile Disk Read Only Memory (DVD-ROM), and a Universal Serial Bus (USB) memory in which the program is stored, Further, the program may be downloaded from an external device through a network.