Abstract:
When an event arises in which at least one of a driver and a passenger of a vehicle needs to be warned of a situation of the vehicle, a first determining unit determines contents of a warning, and a second determining unit determines a risk level of the problematic situation based on the contents of the warning determined by the first determining unit. A display control unit displays information on the situation of the vehicle on display in an interrupting manner in a display mode that is set according to the risk level.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a vehicular display control device that controls display contents to be provided to a driver of a vehicle, and more particularly, to a vehicular display control device that informs the driver of an appropriate warning according to a risk level of a problematic situation of the vehicle. 
         [0003]    2. Description of the Related Art 
         [0004]    Conventionally, vehicles are equipped with a plurality of indicators that keep the passengers riding in a vehicle updated about various situations such as the remaining amount of vehicle fuel or status of turn indicator lamps. 
         [0005]    With the advent of car navigation systems with inbuilt display, a technology to display information and warnings on the inbuilt display is becoming prevalent. 
         [0006]    A car navigation system can be used to display more detailed information about various situations as compared to conventional indicators. Moreover, the displayed information can be varies according depending on the transition in the situations. For example, Japanese Patent Application Laid-Open No. 2006-17652, Japanese Patent Application Laid-Open No. 2002-46505, Japanese Patent Application Laid-Open No. 2002-236955, and Japanese Patent Application Laid-Open No. H10-236243 disclose techniques for repetitively displaying a warning about a problematic situation until the problem is resolved. 
         [0007]    By using the abovementioned technology, passengers riding in a vehicle can be updated about various problematic situations such as low fuel or continuous flashing of a turn indicator lamp. Although the passengers need to be warned about each problematic situation, the risk level of each problem is different if a vehicle is driven with the problem unresolved. For example, while riding in a vehicle, the risk level for low fuel is different than the risk level for a half-shut door. 
         [0008]    Thus, it is necessary not only to inform the passengers about a problematic situation but also to warn how risky it is to ride in a vehicle without resolving the problem. 
         [0009]    However, in a conventional technology, a warning issued to the passengers does not vary according to the risk level of each problematic situation. As a result, in the case of a high risk situation, there is a possibility that a passenger ignores the warning by cancelling the warning display and continues to ride in the vehicle without resolving the problem. On the other hand, in the case of a low risk situation, there is a possibility that a passenger cannot purposely cancel the warning display after reading the warning or the warning is repetitively displayed after being canceled. 
       SUMMARY OF THE INVENTION 
       [0010]    It is an object of the present invention to at least partially solve the problems in the conventional technology. 
         [0011]    According to an aspect of the present invention, there is provided a vehicular display control device including a first determining unit that determines contents of a warning, when an event arises in which at least one of a driver and a passenger of a vehicle needs to be warned of a situation of the vehicle; a second determining unit that determines a risk level of the problematic situation based on the contents of the warning determined by the first determining unit; and a display control unit that displays information on the situation of the vehicle on display in an interrupting manner in a display mode that is set according to the risk level. 
         [0012]    The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a schematic diagram of a vehicular display control device according to a first embodiment of the present invention; 
           [0014]      FIG. 2  is an exemplary diagram for explaining a plurality of problematic situations that may arise in a vehicle, risk levels for those situations, and display modes for the risk levels; 
           [0015]      FIG. 3  is an exemplary diagram for explaining a warning that pops up over other information being displayed on a display screen; 
           [0016]      FIG. 4  is a flowchart for explaining the overall operations performed by the vehicular display device control unit; 
           [0017]      FIG. 5  is a flowchart for explaining the operations performed by the vehicular display device control unit when the risk level of a problematic situation is determined to be high; 
           [0018]      FIG. 6  is a flowchart for explaining the operations performed by the vehicular display device control unit when the risk level of a problematic situation is determined to be moderate; and 
           [0019]      FIG. 7  is a flowchart for explaining the operations performed by the vehicular display device control unit when the risk level of a problematic situation is determined to be low. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. The present invention is not limited to these exemplary embodiments. 
         [0021]      FIG. 1  is a schematic diagram of a vehicular display control device  1  according to a first embodiment of the present invention. The vehicular display control device  1  is connected to a vehicle-body electronic control unit (ECU)  30 , an engine control ECU  60 , and a power management ECU  70  via a bus network. 
         [0022]    The power management ECU  70  manages a vehicle battery and transmits the battery power over the bus network. 
         [0023]    The engine control ECU  60  controls the engine operations depending on the use of an accelerator pedal in the vehicle. The engine control ECU  60  includes a coolant temperature sensor  61  and an exhaust temperature sensor  62 , and transmits information regarding the coolant temperature and the exhaust temperature of the vehicle over the bus network. 
         [0024]    The vehicle-body ECU  30  controls the operations of various equipments and functions provided on the vehicle body. The vehicle-body ECU  30  is connected with a lamp control mechanism  40 , a door switch  51 , a hood switch  52 , a seat belt sensor  53 , a hand break sensor  54 , a washer fluid indicator  55 , a fuel indicator  56 , an oil indicator  57 , and an indicator operating unit  33 . 
         [0025]    The lamp control mechanism  40  controls operations of a plurality of lamps provided on the vehicle. The lamps include turn indicator lamps  41  (i.e., winker lamps), brake lamps (not shown), and head lamps (not shown). Moreover, the lamp control mechanism  40  includes a lamp burnout sensor  42  for detecting burned-out lamps. 
         [0026]    The door switch  51  switches between an OFF state when a vehicle door is open and an OFF state when a vehicle door is closed. Similarly, the hood switch  52  switches between an ON state when the vehicle hood is open and an OFF state when the vehicle hood is closed. 
         [0027]    The seat belt sensor  53  informs the vehicle-body ECU  30  whether seat belts are fastened. Similarly, the hand break sensor  54  informs the vehicle-body ECU whether the hand break is applied. 
         [0028]    The washer fluid indicator  55  informs the vehicle-body ECU  30  when the amount of washer fluid falls below a specific amount. Similarly, the fuel indicator  56  informs the vehicle-body ECU  30  when the amount of vehicle fuel (e.g., gasoline) falls below a specific amount. The oil indicator  57  informs the vehicle-body ECU  30  when the amount of vehicle oil falls below a specific amount. 
         [0029]    The vehicle-body ECU  30  includes a situation determining unit  31  and an indicator control unit  32 . The situation determining unit  31  obtains various information from the power management ECU  70 , the engine control ECU  60 , the lamp control mechanism  40 , the door switch  51 , the hood switch  52 , the seat belt sensor  53 , the hand break sensor  54 , the washer fluid indicator  55 , the fuel indicator  56 , and the oil indicator  57 , and determines whether a problematic situation has arisen in the vehicle for which passengers riding in the vehicle need to be warned. 
         [0030]    When the situation determining unit  31  determines it necessary to issue a warning to the passengers, the indicator control unit  32  controls the indicator operating unit  33  to switch ON an indicator corresponding to the problematic situation. The indicator control unit  32  also transmits details of the warning over the bus network. 
         [0031]    The vehicular display control device  1  includes a control unit  10  and an input-output (I/O) unit  20 . The I/O unit  20  further includes a display screen  21  for displaying various information to the passengers, a speaker  22  for outputting voice information to the passengers, a touch panel  23  from which the passengers can input instructions, and a switch  24 . 
         [0032]    The control unit  10  controls the operations of the I/O unit  20 . More particularly, depending on instructions from the passengers or operating conditions of other equipments in the vehicle, the control unit  10  controls the I/O unit  20  to output information by using the display screen  21  and the speaker  22 . The control unit  10  can control, e.g., car navigation and inform the passengers about routes to a destination or facilities in the vicinity of current location of the vehicle. 
         [0033]    Moreover, the control unit  10  monitors the information transmitted over the bus network. After the vehicle-body ECU  30  transmits details of a warning over the bus network, the control unit  10  obtains the details and pops up the warning over other information being displayed on the display screen  21 . 
         [0034]    The control unit  10  includes a warning determining unit  11 , a risk determining unit  12 , a display control unit  13 , and a monitoring control unit  14 . The warning determining unit  11  monitors the bus network and determines a warning from the information being transmitted over the bus network. 
         [0035]    The risk determining unit  12  determines a risk level for a problematic situation described in the details of a warning. The display control unit  13  controls displaying the warning on the display screen  21  based on a display mode set corresponding to the risk level. 
         [0036]    When a warning is to be issued about a problematic situation, the monitoring control unit  14  starts monitoring that particular situation and varies the risk level depending on the transition in the situation. 
         [0037]    Given below is the description about a plurality of problematic situations that may arise in a vehicle, risk levels for those situations, and display modes for the risk levels with reference to  FIG. 2 . As shown in  FIG. 2 , situations such as riding in a vehicle without fastening a seatbelt, riding in a vehicle while keeping the hand brake in an applied state, riding in a vehicle while keeping flashers ON, and riding in a vehicle while keeping a turn indicator lamp ON are determined to be low-risk situations. 
         [0038]    On the other hand, a situation such as increase in the coolant temperature or the exhaust temperature is determined to be a moderate-risk situation, while a situation such as riding in a vehicle while keeping a door or the vehicle hood half-shut is determined to be a high-risk situation. 
         [0039]    Meanwhile, a situation such as low fuel, low oil, oil deterioration, low washer fluid, or low battery charge is initially determined to be a low-risk situation. Even if such a situation arises, the control unit  10  has some leeway in switching the corresponding indicator ON such that the passengers are warned about the situation. However, the risk level of such a situation changes to moderate or high if the situation gets worse in the course of time. 
         [0040]    For example, in the case of low fuel, the monitoring control unit  14  first determines the situation to be a low-risk situation, starts monitoring the travel distance or the engine status, and varies the risk level to moderate or high depending on the monitoring result. 
         [0041]    Similarly, in the case of low oil or oil deterioration, the monitoring control unit  14  first determines the situation to be a low-risk situation, starts monitoring the travel distance or the engine status, and varies the risk level to moderate or high depending on the monitoring result. In the case of low washer fluid, the monitoring control unit  14  first determines the situation to be a low-risk situation, monitors the number of times for which the washer fluid is consumed thereafter, and varies the risk level to moderate or high as the amount of washer fluid further decreases. Similarly, in the case of low battery charge, the monitoring control unit  14  first determines the situation to be a low-risk situation, monitors the amount of battery charge consumed thereafter, and varies the risk level to moderate or high as the battery charge further decreases. 
         [0042]    In the case of a display mode for a low-risk situation, a warning pops up over other information being displayed on the display screen  21 . However, it is possible for a passenger to cancel the warning display from the display screen  21 . The warning is not redisplayed thereafter. 
         [0043]    In the case of a display mode for a moderate-risk situation, after a warning pops up over other information being displayed on the display screen  21 , it is possible for a passenger to temporarily cancel the warning display. However, the warning is repetitively displayed on the display screen  21  after, e.g., a specific time interval or a specific travel distance until the problem is resolved. 
         [0044]    In the case of a display mode for a high-risk situation, a warning pops up over other information being displayed on the display screen  21 . Moreover, a passenger is not able to cancel the warning display. That is, the warning is continuously displayed until the problem is resolved. 
         [0045]      FIG. 3  is an exemplary diagram for explaining a warning that pops up over other information being displayed on a display screen. The display screen in  FIG. 3  is originally shown to be displaying a music playback screen as selected by the passengers. However, when, e.g., the vehicle fuel falls below a specific amount (a low fuel situation), a warning pops up over the music playback screen. That is, the display of the music playback screen is interrupted by the warning display. 
         [0046]    The warning informs the passengers that the vehicle is on low fuel as well as projects a possible travel distance in the current low fuel situation. Moreover, if the situation is determined to be a low-risk situation or a moderate-risk situation, an OK button is provided on the warning such that the passengers can touch the OK button to at least temporarily cancel the display after reading the warning. 
         [0047]      FIG. 4  is a flowchart for explaining the overall operations performed by the control unit  10 . 
         [0048]    First, the control unit  10  monitors the information transmitted over the bus network (Step S 101 ). When a warning is transmitted by the vehicle-body ECU  30  over the bus network (Yes at Step S 102 ), the warning determining unit  11  determines the details of that warning (Step S 103 ). The risk determining unit  12  then determines a risk level for a problematic situation described in the details of the warning (Step S 104 ). The display control unit  13  controls displaying the warning on the display screen  21  based on a display mode set corresponding to the risk level (Step S 105 ). The system control then returns to Step S 101 . 
         [0049]    The process of displaying a warning on the display screen  21  differs for each risk level, viz., low, moderate, and high. When the risk level is determined to be high as shown in  FIG. 5 , the display control unit  13  first pops up a warning over other information being displayed on the display screen  21  (Step S 201 ) and keeps displaying the warning. When the problem corresponding to the warning is resolved (Yes at Step S 202 ), the display control unit  13  cancels the warning display (Step S 203 ). 
         [0050]    When the risk level is determined to be moderate as shown in  FIG. 6 , the display control unit  13  first pops up a warning over other information being displayed on the display screen  21  (Step S 301 ) and provides an OK button on the warning display such that the passengers can temporarily cancel the warning display after reading the warning (Step S 302 ). 
         [0051]    When the problem corresponding to the warning is resolved (Yes at Step S 303 ), the display control unit  13  cancels the warning display (Step S 307 ). 
         [0052]    However, when the problem corresponding to the warning is not resolved (No at Step S 303 ), the display control unit  13  determines whether the OX button is touched (Step S 304 ). If the OK button is not touched (No at Step S 304 ), the system control returns to Step S 301  and the warning is kept displayed on the display screen  21 . 
         [0053]    If the OK button is touched (Yes at Step S 304 ), the warning display is temporarily cancelled (Step S 305 ). After a certain condition such as a specific time interval or a specific travel distance is satisfied (Yes at Step S 306 ), the system control returns to Step S 301  and the warning is redisplayed on the display screen  21 . 
         [0054]    When the risk level is determined to be low as shown in  FIG. 7 , the display control unit  13  first determines whether a warning has been previously displayed and cancelled (Step S 401 ). Only when the warning is not previously displayed (No at Step S 401 ), the display control unit  13  pops up the warning over other information being displayed on the display screen  21  (Step S 402 ) and provides an OX button on the warning display such that the passengers can permanently cancel the warning display after reading the warning (Step S 403 ). 
         [0055]    When the problem corresponding to the warning is resolved (Yes at Step S 404 ), the display control unit  13  cancels the warning display (Step S 408 ). 
         [0056]    When the problem corresponding to the warning is not resolved (No at Step S 404 ), the display control unit  13  first determines whether the OK button is touched (Step S 405 ). If the OK button is not touched (No at Step S 405 ), the system control returns to Step S 402  and the warning is kept displayed on the display screen  21 . 
         [0057]    If the OK button is touched (Yes at Step S 405 ), the display control unit  13  cancels the warning display (Step S 406 ) and stores the history of displaying the warning and then cancelling the warning display (Step S 407 ). Such history is stored for each displayed warning and deleted after a predetermined amount of time. The vehicular display control device  1  can be configured to delete such history at the time of, e.g., switching OFF the engine or turning the power of the vehicle ON for first time in a day. 
         [0058]    To sum up, the vehicular display control device  1  according to the first embodiment detects a problematic situation in a vehicle, determines the risk level corresponding to the situation, and issues a warning to the passengers by using a display mode appropriate for the determined risk level. 
         [0059]    Thus, when a high-risk situation such as riding in a vehicle while keeping a door or the vehicle hood half-shut arises, the warning is continuously displayed without allowing the passengers to cancel the warning display. On the other hand, when a low-risk situation such as riding in a vehicle without fastening a seatbelt arises, the passengers are allowed to cancel the warning display. 
         [0060]    As a result, it is possible to correctly warn the passengers about the risk level of a problematic situation thereby improving the reliability of the vehicular display control device  1  and contributing to driving safety. 
         [0061]    Moreover, e.g., in the case of low oil or oil deterioration, the risk level keeps changing depending on the remaining amount of the oil or the degree of oil deterioration, respectively. Thus, as soon as such situations arise, the travel distance or the engine status is continuously monitored such that the risk level can be varied according to the changing monitoring results. Such a configuration facilitates in simplifying the monitoring mechanism as well as achieving efficient monitoring. 
         [0062]    In addition to detecting a burned-out lamp by using the lamp control mechanism  40 , a warning can be displayed to inform the passengers about the burned-out lamp. Moreover, if the burned-out lamp happens to be a head lamp, it is possible to vary the risk level depending on the time of day. 
         [0063]    Furthermore, the risk levels are not limited to low, moderate, and high, and can be appropriately set along with the corresponding display modes. 
         [0064]    Moreover, instead of controlling the display screen  21 , the vehicular display control device  1  can be configured to control an external display device. 
         [0065]    As described above, according to an aspect of the present invention, it is possible to control the display of a warning according to the risk level of a problematic situation and hence contribute to driving safety. 
         [0066]    Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.