JP2017049646A - Driving support system and driving support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving support system and a driving support device which are capable of reducing the possibility of performing an unnecessary notification to a driver.SOLUTION: A driving support system 100 comprises a driving support device 2 used in an automobile and a portable terminal 1 carried by pedestrians or bicycle riders. The portable terminal 1 transmits radio signals at fixed intervals, and the driving support device 2 comprises a radio reception part for receiving the radio signals. The driving support device 2 accumulates, in a RAM 212, reception strengths of signals received by the radio reception part within a fixed period of time and determines whether the reception strengths have an increasing tendency. Then, if the vehicle speed of the own vehicle is less than a prescribed speed which is the maximum speed that can be regarded as a slow speed and the reception strengths have an increasing tendency, it displays information indicating that there is a moving body that is approaching the own vehicle in a display.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a driving support system and a driving support device that notify a driver of information about a moving object existing around a vehicle.

  2. Description of the Related Art Conventionally, a driving support device that is used in a vehicle and detects a moving body existing around the vehicle and notifies the driver of information about the moving body, and the driving support device that supports the driving operation of the driver, and the driving support Various driving support systems including devices have been proposed.

  For example, Patent Literature 1 discloses a driving support system including a portable terminal that is carried by a pedestrian and is configured to function as a transmission device that sequentially transmits a radio signal having a predetermined frequency. The driving support device included in the driving support system disclosed in Patent Document 1 is configured to receive a radio signal transmitted from a mobile terminal. When receiving a wireless signal transmitted from the mobile terminal, the driving support device outputs a predetermined warning sound from a speaker mounted on the vehicle to warn the driver of the presence of a pedestrian.

Japanese Patent Laid-Open No. 2-5200

  In the configuration of Patent Document 1, an alarm sound is output every time a vehicle travels in the vicinity of a pedestrian carrying a mobile terminal. Therefore, even when the vehicle is traveling along a road at a cruising speed (for example, 40 km / h), even if the vehicle overtakes a pedestrian existing on the sidewalk, the mobile terminal carried by the pedestrian When a wireless signal is received, an alarm sound is emitted.

  That is, in the configuration of Patent Document 1, the notification may be executed even in a situation where it is unnecessary to notify that there is a pedestrian carrying the mobile terminal. Such unnecessary notifications can be annoying to the driver.

  The present invention has been made based on this situation, and an object of the present invention is to provide a driving support system and a driving support device that can reduce the risk of performing unnecessary notification.

  The invention of a driving support system for achieving the object includes a driving support device (2) used in an automobile, and a moving body side device mounted or carried on a moving body existing outside the automobile in which the driving support device is used. (1) is a driving support system including a mobile unit side device including a transmission unit (13) that transmits a radio signal in a frequency band assigned in advance intermittently or continuously. A reception unit (22) that receives a radio signal in a frequency band, a reception strength acquisition unit (F3) that acquires a reception strength that is a signal strength of the radio signal received by the reception unit, and a reception strength acquisition unit An intensity transition determination unit (F4) that determines whether or not the received reception strength is increasing, a vehicle speed acquisition unit (F11) that sequentially acquires the current vehicle speed of the vehicle, and a driver that is in the vicinity of the vehicle. A notification unit (F6) that outputs information for notification, and the notification unit is configured such that the vehicle speed acquired by the vehicle speed acquisition unit is less than a prescribed speed corresponding to an upper limit of a speed that can be regarded as a slow speed. In addition, when it is determined by the intensity transition determination unit that the reception intensity is increasing, information indicating that there is a moving body approaching the automobile is output.

  In the above configuration, when the vehicle speed is less than the specified speed and the strength transition determination unit determines that the reception strength is increasing, there is a moving body that is approaching the host vehicle. Information indicating that it is to be performed (hereinafter referred to as approach notification information) is output. In addition, the own vehicle here refers to the motor vehicle in which the driving assistance apparatus is mounted.

  According to such an aspect, first, when the vehicle speed of the host vehicle is equal to or higher than the specified speed, the notification unit does not output the approach notification information. Therefore, for example, when driving along a road, the risk of outputting approach notification information to the driver is reduced when overtaking a moving body (for example, a pedestrian or bicycle) on the sidewalk. Is done. This is because when the host vehicle is traveling along a road, there is a high possibility that the vehicle speed is equal to or higher than the specified speed.

  Further, according to the above-described configuration, the fact that the reception intensity tends to increase is a condition for outputting approach notification information (hereinafter referred to as an approach notification condition). If the moving body is moving in a direction away from the host vehicle, the temporal change in the reception intensity tends to decrease. Therefore, according to the above configuration, it is possible to reduce the possibility of outputting the approach notification information due to the radio signal emitted from the moving body moving away from the host vehicle.

  In general, a moving body moving in a direction away from the host vehicle is less likely to come into contact with the host vehicle. It can be said that the information about the moving body that is moving away from the host vehicle is less useful to the driver than the information about the moving body that is approaching the host vehicle.

  Therefore, by including that the reception strength is increasing as a notification condition, it is possible to reduce the possibility of outputting information with relatively low usefulness. That is, according to the above configuration, it is possible to suppress the possibility of performing unnecessary notification.

  An invention of a driving support device for achieving the above object is used in an automobile, and includes a notification unit (F6) that outputs information for notifying a driver of the automobile about a moving body existing around the automobile. A receiving unit (22) for receiving a radio signal transmitted from a mobile unit device mounted on or carried by a mobile unit existing outside the automobile, and a signal of the radio signal received by the receiver unit A reception strength acquisition unit (F3) that acquires a reception strength that is a strength, an intensity transition determination unit (F4) that determines whether or not the reception strength acquired by the reception strength acquisition unit is increasing, A vehicle speed acquisition unit (F11) that sequentially acquires the current vehicle speed, and a notification unit (F6) that outputs information for notifying the driver of a moving body existing around the vehicle. But When the obtained vehicle speed is less than the prescribed speed corresponding to the upper limit of the speed that can be regarded as the slow speed, and the strength transition judging unit judges that the received strength is increasing, Information indicating that there is an approaching moving body is output.

  The driving support device corresponds to the driving support device used in the driving support system described above. That is, according to the above structure, there exists an effect similar to the above-mentioned driving assistance system.

  In addition, the code | symbol in the parenthesis described in the claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is limited is not.

It is a figure which shows an example of the schematic structure of the driving assistance system 100 which concerns on this embodiment. 2 is a block diagram illustrating an example of a schematic configuration of a mobile terminal 1. FIG. 2 is a block diagram illustrating an example of a schematic configuration of a driving support device 2. FIG. 3 is a block diagram for explaining a schematic configuration of a vehicle-side control unit 21. FIG. It is a flowchart for demonstrating a notification related process. It is a figure for demonstrating the effect of 1st Embodiment. It is a figure for demonstrating the effect of 2nd Embodiment. It is a figure for demonstrating the effect of 2nd Embodiment. It is a figure for demonstrating the action | operation of 2nd Embodiment. It is a figure for demonstrating the structure of the portable terminal 1 in the modification 2, and the driving assistance device 2. FIG.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an example of a schematic configuration of a driving support system 100 according to the present invention. The driving support system 100 includes a portable terminal 1 that is carried by a person such as a pedestrian or a bicycle driver who can be present outside the traveling automobile M, and a driving assistance apparatus 2 mounted on the automobile M. I have.

  Although only one mobile terminal 1 is illustrated in FIG. 1, the driving support system 100 may include a plurality of mobile terminals 1. Although only one driving support device 2 is shown in FIG. 1, the driving support system 100 as a whole may be provided with a plurality of driving support devices 2 by being mounted in each of a plurality of automobiles. . Hereinafter, the configuration and operation of the mobile terminal 1 and the driving support device 2 will be described more specifically.

<About mobile terminal 1>
First, the configuration and operation of the mobile terminal 1 will be described. For convenience, a person carrying the mobile terminal 1 is referred to as a user. The portable terminal 1 corresponds to the mobile unit device described in the claims. As shown in FIG. 2, the portable terminal 1 includes a portable control unit 11, a storage unit 12, a wireless transmission unit 13, and a power source 14.

  The portable side control unit 11 is connected to each of the storage unit 12, the wireless transmission unit 13, and the power source 14, and controls the operation of the entire portable terminal 1. The functions of the portable control unit 11 will be described later separately. The storage unit 12 is realized using a nonvolatile storage medium such as a ROM or a flash memory. The storage unit 12 stores programs, setting data, and the like for the portable side control unit 11 to execute various processes.

  The wireless transmission unit 13 includes an antenna for transmitting a wireless signal in a frequency band that can be received by the driving support device 2 described later, and transmits a wireless signal based on an instruction from the mobile-side control unit 11. The transmission power of the wireless signal transmitted from the wireless transmission unit 13 may be set so that the reach distance of the wireless signal is about several tens of meters, for example. Note that the transmission power of the wireless signals output sequentially is configured to be substantially constant.

  In the present embodiment, it is assumed that the driving support device 2 has a configuration capable of receiving a radio signal in the UHF (Ultra High Frequency) band, more specifically, a radio signal in the 300 MHz band. Accordingly, the wireless transmission unit 13 in the present embodiment is configured to transmit a 300 MHz band wireless signal.

  Note that the frequency of the radio signal transmitted by the radio transmission unit 13 may be any frequency that can be received by the driving support device 2 and may be a frequency in a frequency band other than the 300 MHz band. What is necessary is just to design according to the frequency which the driving assistance device 2 can receive.

  The power supply 14 supplies power to the portable side control unit 11. For example, as the power source 14, a battery or the like can be used. Note that the supply of power by the power source 14 may be controlled (supplied / shut off) by the portable control unit 11.

  The portable control unit 11 is configured as a computer, and includes a CPU, RAM, ROM, input / output interface (hereinafter referred to as I / O) (not shown), a bus line that connects these configurations, and the like.

  The portable control unit 11 outputs an instruction signal instructing the wireless transmission unit 13 to transmit a wireless signal at a predetermined time interval (for example, every 500 milliseconds). As a result, the wireless transmission unit 13 transmits wireless signals at predetermined time intervals.

  When the mobile terminal 1 is configured to detect the moving speed of the mobile terminal 1, the mobile control unit 11 dynamically changes the transmission interval of the radio signal according to the moving speed of the mobile terminal 1. You may do it. In that case, the portable side control part 11 shall shorten a transmission interval, so that the moving speed of the portable terminal 1 is large. Further, the wireless transmission unit 13 may transmit wireless signals continuously instead of intermittently.

  The portable terminal 1 should just be provided with the member and function which were mentioned above. The portable terminal 1 does not have to be a device dedicated to the driving support system 100. For example, a known mobile phone such as a smartphone, a tablet terminal, a wearable device, a portable music player, a portable game machine, or the like may be used as the portable terminal 1.

  Moreover, the portable terminal 1 may be a portable device for vehicles used in a known keyless entry system. The keyless entry system is based on reception of a radio signal transmitted from a vehicular portable device that is associated with the vehicular portable device that transmits a radio signal based on a user operation and the vehicular portable device. It is a system provided with the vehicle equipment which performs locking / unlocking of a vehicle door, etc. A vehicle portable device used in a keyless entry system is provided with a switch for instructing locking of a door or instructing unlocking.

  Furthermore, the portable terminal 1 may be a vehicle portable device used in a known smart entry system. The smart entry system refers to an on-board device installed in a vehicle owned by a user and a portable device for a vehicle that performs collation by wireless communication. This is a system that executes various controls such as starting.

  In both the keyless entry system and the smart entry system, the in-vehicle device includes a receiving device for receiving a radio signal transmitted from the vehicular portable device. A keyless entry system or a smart entry system (hereinafter referred to as a keyless entry system or the like) corresponds to the vehicle electronic key system described in the claims.

<About the driving support device 2>
Next, the driving support device 2 will be described. The driving support device 2 is mounted on the automobile M as described at the beginning. In the present embodiment, the driving support device 2 is mounted on the automobile M. However, as another aspect, the driving assistance apparatus 2 may be brought into the automobile M by the user. Moreover, the aspect mounted in the motor vehicle M includes not only an aspect incorporated in the motor vehicle M but also an aspect in which it is detachably attached to a holder or the like provided in the motor vehicle M.

  As the automobile M, for example, various vehicles traveling on a road such as a passenger car, a bus, and a truck are applicable. In FIG. 1, an automobile is exemplified as the automobile M, but the automobile M may be a motorcycle, an automobile tricycle, or the like, or may be another automobile. For convenience, the automobile M on which the driving support device 2 is mounted is also referred to as the own vehicle.

  As shown in FIG. 3, the driving support device 2 includes a vehicle-side control unit 21, a wireless reception unit 22, a speaker 23, a display 24, an ignition switch 25, an accelerator sensor 26, a brake sensor 27, a vehicle speed sensor 28, and a shift position sensor. 29.

  The vehicle-side control unit 21 is communicably connected to each of the wireless reception unit 22, the speaker 23, the display 24, the ignition switch 25, the accelerator sensor 26, the brake sensor 27, the vehicle speed sensor 28, and the shift position sensor 29. The vehicle-side control unit 21 controls the operation of the entire driving support device 2 based on data and signals input from each unit connected to itself, such as the vehicle speed sensor 28, for example. Details of the vehicle-side control unit 21 will be described later.

  The wireless reception unit 22 includes an antenna for receiving a wireless signal transmitted from the mobile terminal 1, and receives a wireless signal transmitted from the mobile terminal 1 via the antenna. The operation of the wireless reception unit 22 is controlled by the vehicle side control unit 21.

  Specifically, based on the input of a control signal instructing to operate from the vehicle-side control unit 21, the state shifts to a state in which a radio signal can be received (hereinafter referred to as an active state). Further, the operation is stopped based on the input of a control signal instructing to stop the operation from the vehicle side control unit 21. The state in which the operation is stopped (hereinafter referred to as the sleep mode) is a state in which power consumption is less than that in a state in which a wireless signal can be received. The state where the power consumption is low includes a state where the power consumption is zero.

  In addition, the wireless reception unit 22 includes a reception strength detection unit 221 that detects the signal strength (hereinafter, reception strength) of the received wireless signal. The reception intensity detection unit 221 may be realized using a known reception intensity detection circuit. The reception intensity detected by the reception intensity detection unit 221 is sequentially provided to the vehicle side control unit 21. The reception strength here corresponds to a parameter generally called RSSI (Received Signal Strength Indication).

  The wireless receiving unit 22 can be realized by using a receiving device used in a keyless entry system or the like. As described above, if an existing receiving device used in a keyless entry system or the like is used as the wireless receiving unit 22, it is possible to reduce the cost of newly installing the receiving equipment for the driving support device 2 separately. That is, the cost for mounting the function as the driving support device 2 on the host vehicle M can be suppressed.

  In recent years, a vehicle equipped with a tire pressure monitoring system (hereinafter TPMS: Tire Pressure Monitoring System) that directly measures the air pressure and temperature inside the tire with a sensor and wirelessly transmits the information to the receiving device on the vehicle body side. Is also popular. When the host vehicle M is also a vehicle on which the TPMS is mounted, a receiving device used in the TPMS may be used as the wireless receiving unit 22. As described above, if an existing receiving device used in TPMS is used as the wireless receiving unit 22, it is possible to reduce the cost of newly installing a receiving facility for the driving support device 2.

  The speaker 23 converts the voice data input from the vehicle side control unit 21 into voice (including simple sound) and outputs the voice. For example, the speaker 23 outputs a warning sound based on an instruction from the vehicle-side control unit 21.

  The display 24 displays an image or text based on a control signal input from the vehicle side control unit 21. The display 24 may be provided, for example, in an area corresponding to the center of the instrument panel in the vehicle width direction or the front of the driver's seat. The display 24 is capable of full color display, for example, and can be configured using a liquid crystal display, an organic EL display, or the like. The display 24 may be a head-up display.

  The ignition switch 25 is a switch for starting the engine of the host vehicle M, and outputs a signal corresponding to on / off of the switch. The accelerator sensor 26 is a sensor that detects the amount of depression of an accelerator pedal mounted on the host vehicle M. The accelerator sensor 26 outputs a signal corresponding to the depression amount of the accelerator pedal.

  The brake sensor 27 is a sensor that detects the amount of depression of a brake pedal mounted on the host vehicle M. The brake sensor 27 outputs a signal corresponding to the depression amount of the brake pedal. The vehicle speed sensor 28 is a sensor that detects the vehicle speed of the host vehicle M. The vehicle speed sensor 28 outputs a signal corresponding to the vehicle speed of the host vehicle M.

  The shift position sensor 29 is a sensor that detects the shift position of the host vehicle M, and outputs a signal corresponding to the detected position. Shift position types include drive position, reverse position, neutral position, and parking position.

  The drive position is a shift position that transmits the driving force generated by the engine or motor mounted on the host vehicle M to the drive wheels so that the host vehicle M moves forward. The reverse position is a shift position that transmits the above-described driving force to the driving wheels so that the host vehicle M moves backward. The neutral position is a shift position where the driving force is not transmitted to the driving wheel, and the parking position is a shift position where the driving force is not transmitted to the driving wheel and locked so that the driving wheel does not rotate.

  The signals output from the ignition switch 25, the accelerator sensor 26, the brake sensor 27, the vehicle speed sensor 28, and the shift position sensor 29 are configured to be input to the vehicle-side control unit 21 via, for example, an in-vehicle network (not shown). Has been.

<About the vehicle-side control unit 21>
Next, the vehicle side control part 21 is demonstrated. The vehicle-side control unit 21 is configured as a computer and includes a CPU 211, a RAM 212, a ROM 213, an I / O, and a bus line that connects these configurations, as shown in FIG.

  The ROM 213 stores a program (hereinafter referred to as a vehicle program) for causing a normal computer to function as the vehicle-side control unit 21 in the present embodiment, various setting data, and the like. In addition, the above-mentioned vehicle program should just be stored in non-volatile storage media, such as ROM213. The CPU 211 executing the vehicle program corresponds to executing a method corresponding to the vehicle program.

  As shown in FIG. 4, the vehicle-side control unit 21 includes a vehicle information acquisition unit F1, a communication control unit F2, a reception intensity management unit F3, an intensity transition determination unit F4, as functional blocks realized by executing the vehicle program. An acceleration operation determination unit F5 and a notification processing unit F6 are provided. In addition, you may implement | achieve each functional block with which the vehicle side control part 21 is provided as hardware by one or some IC etc. FIG.

  The vehicle information acquisition unit F1 acquires various information (hereinafter referred to as vehicle information) indicating the traveling state of the host vehicle M from various sensors mounted on the host vehicle M. For example, the vehicle information acquisition unit F1 acquires information indicating whether or not the ignition power is on based on a signal output from the ignition switch 25.

  Further, the vehicle information acquisition unit F1 acquires the accelerator pedal depression amount, the brake pedal depression amount, the vehicle speed, the shift position, and the like from the accelerator sensor 26, the brake sensor 27, the vehicle speed sensor 28, and the shift position sensor 29, respectively. . The acquired various information may be sorted and stored in the RAM 212 in time series for each type of information. For convenience, the function of acquiring the vehicle speed from the vehicle speed sensor 28 among the functions of the vehicle information acquisition unit F1 is referred to as a vehicle speed acquisition unit F11.

  In addition, the information which the vehicle information acquisition part F1 acquires is not restricted to what was mentioned above. For example, when an acceleration sensor that detects acceleration acting in the longitudinal direction of the vehicle is mounted on the host vehicle M, the vehicle information acquisition unit F1 may acquire the detection result of the acceleration sensor. Moreover, the vehicle information acquisition part F1 does not need to acquire all the types of information mentioned above. The vehicle information acquisition part F1 should just acquire the information which shows a vehicle speed at least.

  The vehicle information acquisition unit F1 is configured to be able to acquire the type information for the acceleration operation determination unit F5 described later to determine whether or not the driver has performed an operation for accelerating the host vehicle M (hereinafter, acceleration operation). It is preferable that The accelerating operation here includes a preparatory operation for accelerating, an operation allowing acceleration by gravity, and an operation for starting from a parked state. The information for the acceleration operation determination unit F5 to determine whether or not the acceleration operation by the driver has been performed corresponds to, for example, a vehicle speed, an accelerator pedal depression amount, a brake pedal depression amount, a shift position, and the like.

  The communication control unit F <b> 2 controls the operation of the wireless reception unit 22. That is, a control signal for shifting from the sleep mode to the active mode is output, or a control signal for shifting from the active mode to the sleep mode is output. The timing for outputting various control signals will be described later separately.

  The reception intensity management unit F3 sequentially acquires the reception intensity output from the wireless reception unit 22 (for example, every 100 milliseconds). Also, the received intensities acquired within a certain time (for example, 5 seconds) from the present are arranged in chronological order and stored in the RAM 212. For convenience, data in which received intensities are arranged in time series is referred to as intensity transition data. The time for storing the acquired reception strength in the RAM 212 may be designed as appropriate, but at least the length of time that the strength transition determination unit F4 can determine whether or not the reception strength tends to increase is used. The reception intensity management unit F3 corresponds to the reception intensity acquisition unit described in the claims.

  The intensity transition determination unit F4 refers to the intensity transition data stored in the RAM 212 and determines whether or not the reception intensity tends to increase. A known method may be used as a method for determining whether or not the reception intensity tends to increase. For example, when the latest reception strength is larger than the reception strength acquired last time, it may be determined that the reception strength tends to increase.

  The acceleration operation determination unit F5 determines whether or not an acceleration operation by the driver has been performed based on the vehicle information acquired by the vehicle information acquisition unit F1. The case where it is determined that the acceleration operation by the driver is performed may be, for example, a case where the depression amount of the brake pedal becomes 0 in a state where the shift position is a position where the driving force is transmitted to the driving wheel. . Further, when the accelerator pedal depression amount increases, it may be determined that the acceleration operation by the driver has been performed. Furthermore, when the vehicle speed increases, it may be determined that an acceleration operation by the driver has been performed. In addition, the acceleration operation determination unit F5 may determine whether an acceleration operation by the driver has been performed using a known method.

  The notification processing unit F6 performs processing for providing various information to the driver of the host vehicle M via the display 24, the speaker 23, and the like. For example, the notification processing unit F6 performs a process (hereinafter referred to as an approach notification process) for notifying that there is a user approaching the host vehicle M when a predetermined notification condition is satisfied. In addition, the notification processing unit F6 outputs an alarm sound from the speaker 23 when a predetermined alarm condition is satisfied. Details of approach notification processing, notification conditions, and alarm conditions will be described later.

  Note that the device used to provide information to the driver is not limited to the display 24 and the speaker 23. An indicator such as an LED or a vibrator that generates vibration may be used. Various types of information may be output in a form that can be perceived by humans, such as an image, text display, light emission, vibration, and voice. The notification processing unit F6 corresponds to the notification unit described in the claims.

<Notification-related processing>
Next, the notification related process which the vehicle side control part 21 implements is demonstrated using the flowchart shown in FIG. The notification-related process is a process for notifying the driver of the host vehicle M of the presence of the user.

  The flowchart shown in FIG. 5 may be started when, for example, a signal indicating that the ignition power of the host vehicle M is turned on is input from the ignition switch 25. In addition, if this flow ends while the ignition power is on, it may be started again. That is, the notification-related processing may be executed sequentially while the ignition power is on.

  Note that the flowchart shown in FIG. 5 is not limited to the case where the ignition power source is turned on, but may be started and sequentially executed when the host vehicle M is in a power state in which the vehicle M can travel. Each of the following steps is executed by the vehicle-side control unit 21.

  First, in step S1, it is determined whether or not the current vehicle speed V acquired by the vehicle information acquisition unit F1 is less than a specified speed Vth corresponding to an upper limit of a speed range that can be regarded as a slow speed. The slow speed here corresponds to a speed at which the driver can immediately stop the host vehicle M. The slow speed is generally about 5 km / h or 10 km / h. A specific value of the specified speed Vth may be designed as appropriate. Here, as an example, the specified speed Vth is 10 km / h. Of course, the prescribed speed Vth may be other values, such as 5 km / h or 15 km / h.

  If the vehicle speed V is less than the specified speed Vth, an affirmative determination is made in step S1 and the process proceeds to step S2. On the other hand, if the vehicle speed V is not less than the specified speed Vth, a negative determination is made in step S1, and step S1 is performed again. The interval when step S1 is repeatedly performed may be, for example, 100 milliseconds.

  In step S2, the communication control unit F2 outputs a control signal for causing the wireless reception unit 22 to shift from the sleep mode to the active mode, starts reception of the wireless signal, and proceeds to step S3. In step S3, the reception intensity management unit F3 acquires the reception intensity of the radio signal, stores it in the RAM 212, and proceeds to step S4. That is, in this step S3, the latest received intensity is added to the intensity transition data.

  In step S4, the intensity transition determination unit F4 determines whether or not the reception intensity tends to increase based on the intensity transition data stored in the RAM 212. Generally, the reception intensity of a radio signal is larger as it is closer to the transmission source, and is smaller as it is farther away.

  Therefore, the situation where the reception intensity tends to increase means a situation where the wireless signal transmission source and the host vehicle M are approaching. In the present embodiment, the wireless signal transmission source to be received by the wireless reception unit 22 is the mobile terminal 1. That is, determining whether or not the reception intensity tends to increase corresponds to determining whether or not the user carrying the mobile terminal 1 is approaching the host vehicle M.

  When the user carrying the portable terminal 1 is walking, the determination process in step S4 corresponds to determining whether or not there is a pedestrian approaching the host vehicle M. Further, when the user carrying the mobile terminal 1 is driving a bicycle, the determination process in step S4 corresponds to determining whether there is a bicycle approaching the host vehicle M or not. To do.

  Pedestrians and bicycles are preferably moving bodies (hereinafter referred to as notification target moving bodies) whose presence is preferably recognized by the driver of the automobile M. That is, the determination process of step S4 can be regarded as a step of determining whether there is a notification target moving body that is approaching the host vehicle M.

  Note that the moving body approaching the host vehicle M refers to a moving body whose distance from the host vehicle M decreases with the passage of time. That is, even if the moving body is stopped, the moving body whose distance from the own vehicle M is reduced due to the movement of the own vehicle M also corresponds to the moving body approaching the own vehicle M.

  When the intensity transition determination unit F4 determines that the reception intensity is increasing, step S4 is affirmed and the process proceeds to step S5. On the other hand, if it is determined that the reception strength is not increasing, a negative determination is made in step S4 and the process proceeds to step S11.

  In step S5, the notification processing unit F6 performs an approach notification process, and proceeds to step S6. In the approach notification process, the notification processing unit F6 outputs information indicating that there is a user approaching the host vehicle M in a manner that the driver can visually perceive. Specifically, an image or text indicating that there is a user approaching the host vehicle M is displayed on the display 24. For convenience, an image or text indicating that a user carrying the mobile terminal 1 is approaching the host vehicle M is referred to as approach notification information. The display of the approach notification information on the display 24 is held until step S9 is executed.

  The notification processing unit F6 may execute the approach notification process using an indicator realized using an LED or the like. Specifically, an indicator for notifying the driver that there is a user approaching the host vehicle M may be emitted with a predetermined light emission pattern. The parameters constituting the light emission pattern include the presence / absence of blinking, the blinking interval, the lighting color, and the like. Further, the notification processing unit F6 may perform both the approach notification process using the indicator and the approach notification process using the display 24.

  By the way, the case where this step S5 is performed is a case where it is determined that the vehicle speed V is less than the specified speed Vth and that the reception intensity tends to increase. That is, it is determined that the vehicle speed V is less than the specified speed Vth and that the reception intensity tends to increase.

  In step S6, the reception intensity management unit F3 acquires the current reception intensity of the radio signal, stores it in the RAM 212, and proceeds to step S7, as in step S3.

  In step S7, the intensity transition determination unit F4 determines whether or not the reception intensity tends to increase based on the intensity transition data stored in the RAM 212, as in step S4 described above. If it is determined that the reception strength is increasing, step S7 is affirmed and the process proceeds to step S9. On the other hand, if it is determined that the reception intensity is not increasing, a negative determination is made in step S7 and the process proceeds to step S8.

  In step S8, the notification processing unit F6 cancels the display of the approach notification information on the display 24 (in other words, ends), and proceeds to step S11.

  In step S9, the acceleration operation determination unit F5 determines whether an acceleration operation by the driver has been performed based on the vehicle information sequentially acquired by the vehicle information acquisition unit F1. Here, when it is determined that the acceleration operation by the driver has been performed, an affirmative determination is made in step S9 and the process proceeds to step S10. On the other hand, when it is determined that the acceleration operation by the driver is not performed, a negative determination is made in step S9, and the process proceeds to step S6.

  In step S10, the notification processing unit F6 outputs an alarm sound from the speaker 23 and proceeds to step S11. The output of the warning sound is for urging the driver to pay attention to surrounding traffic conditions. The alarm sound output time may be about several seconds.

  In the present embodiment, an alarm sound is output to prompt the driver to pay attention to surrounding traffic conditions, but the present invention is not limited thereto. The driver may be alerted to the surrounding traffic situation by outputting a voice message to the effect that there is an approaching moving body. In addition, attention may be urged by vibrating a vibrator (not shown) incorporated in the steering or driver seat.

  Further, attention may be urged by changing the display mode of the approach notification information on the display 24 to a display mode that attracts the driver's eyes. Of course, as information different from the approach notification information, an image or text that calls attention to surrounding traffic conditions may be displayed on the display 24.

  In step S11, it is determined whether or not the current vehicle speed V acquired by the vehicle information acquisition unit F1 is less than the specified speed Vth. If the vehicle speed V is less than the specified speed Vth, an affirmative determination is made in step S11 and the process returns to step S3. On the other hand, if the vehicle speed V is equal to or higher than the specified speed Vth, a negative determination is made in step S11 and the process proceeds to step S12.

  In step S12, the communication control unit F2 outputs a control signal for causing the wireless reception unit 22 to shift from the active mode to the sleep mode, stops the operation, and ends this flow. Note that if the conditions for starting the notification-related processing are still satisfied at the timing when this flow ends, the processing may be started again from step S1.

<Summary of Embodiment>
In the above configuration, when the vehicle speed V is less than the specified speed Vth and it is determined that the reception intensity tends to increase, the notification processing unit F6 outputs approach notification information. Specifically, an image or text as approach notification information is displayed on the display 24.

  According to such an aspect, first, when the vehicle speed V is equal to or higher than the specified speed Vth, the approach notification information is not output. Therefore, for example, in the situation where the vehicle is traveling along a road, the risk of outputting approach notification information is reduced when the user as a pedestrian existing on the sidewalk is overtaken. This is because in a situation where the vehicle is traveling along a road, there is a high possibility that the vehicle speed is higher than a specified speed.

  Note that, in the process of overtaking a user as a pedestrian, the distance between the user and the host vehicle M becomes smaller, so it is assumed that the reception intensity tends to increase. If the notification condition does not include that the vehicle speed V is less than the specified speed Vth, the approach notification information is output even in a situation where a user as a pedestrian existing on the sidewalk is overtaken. become. The approach notification information output in such a situation is information that is not useful to the driver and may cause trouble.

  According to the configuration of the present embodiment, it is possible to reduce the output of approach notification information in a scene where the usefulness is relatively lowered. In other words, it is possible to reduce the risk of notification of information unnecessary for the driver.

  On the other hand, as a scene where the driver sets the vehicle speed V to be lower than the specified speed Vth, for example, a case where the vehicle passes through an intersection with poor visibility, a case where the vehicle turns right or left, or a case where the vehicle starts from a stop state. These scenes are more likely to come into contact with other moving objects such as pedestrians and bicycles than when traveling on a road (so-called link) connecting intersections on a traffic flow. Therefore, it can be said that the output of approach notification information indicating that there is an approaching user is relatively useful information for the driver.

  In other words, according to the above configuration, it is possible to notify the driver that there is an approaching user in a scene where it is necessary to notify that there is an approaching user while suppressing the fear of notifying unnecessary information. Can do.

  In the above configuration, the notification processing unit F6 continues to output the approach notification information while the reception strength continues to increase. Therefore, the possibility that the driver misses the approach notification information can be reduced.

  Further, in the above configuration, it is further determined that the acceleration operation is performed by the acceleration operation determination unit F5 in the situation where the vehicle speed V is less than the specified speed Vth and the reception intensity is determined to be increasing. If it is, an alarm sound is output.

  Auditory information such as a warning sound is perceived by the driver regardless of the direction of the driver's line of sight. Therefore, according to the above configuration, even when the driver is not aware that the approach notification information is output to the display 24, it can be recognized through hearing that there is an approaching user. .

  In particular, the situation in which the reception intensity is determined to be increasing is a state in which the user is approaching the host vehicle M. In such a case, performing the acceleration operation is relatively likely not aware of the presence of a user approaching the host vehicle M.

  Therefore, according to the above configuration, in a situation where it is assumed that the driver is not aware of the presence of the user approaching the host vehicle M, an alarm sound can be output to appeal for safety confirmation of the surroundings. .

  On the other hand, in the above configuration, even when the user is approaching the host vehicle M, only a visual notification is performed and no alarm sound is output unless the driver performs an acceleration operation. This is because the driver may recognize the presence of a user approaching the host vehicle M. Even when the driver recognizes the presence of the user, if the warning sound is output, the driver may be bothered. In addition, when the driver can recognize the presence of a user approaching the host vehicle M, the acceleration operation is usually difficult to perform.

  Therefore, unnecessary alarm sound output can be suppressed by including the presence or absence of the acceleration operation as the alarm condition. As a result, it is possible to reduce the risk of annoying the driver.

  In addition, by including that the reception strength tends to increase as the notification condition or the alarm condition, even if the user is still staying around the own vehicle M, the user moves away from the own vehicle M. If it is, no approach notification information or alarm sound is output. Therefore, output of unnecessary information can be suppressed.

  Furthermore, when the user has approached from any direction by making the antenna provided in the wireless receiving unit 22 an omnidirectional antenna or arranging a plurality of directional antennas so as to cover all directions of the host vehicle M Even so, the notification processing unit F6 can output approach notification information. For example, even when the user is approaching from behind the host vehicle M, the driver can be notified of the user.

  In the above configuration, since the mobile terminal 1 only needs to transmit a radio signal in a frequency band that can be received by the driving support device 2, a device for other uses such as a mobile terminal for a vehicle, for example. Can be used as the portable terminal 1.

  Furthermore, since the radio signal transmitted by the mobile terminal 1 does not have to be a specific data modulated, the configuration of the radio transmission unit 13 can be simplified. In addition, since the oscillator used in the transmission circuit can be one having a relatively low frequency accuracy, the cost required for the members constituting the mobile terminal 1 can be reduced.

  Furthermore, as described above, when a vehicle portable device used in a keyless entry system or the like is caused to function as the portable terminal 1, it is possible to suppress a contact accident between a pedestrian and a car M particularly in a parking lot or the like. I can expect. Specifically, it is as follows.

  FIG. 6 is a conceptual diagram showing a situation where the car M and the user W1 as a pedestrian are moving so as to approach each other in the parking lot. A user W1 illustrated in FIG. 6 is a person who carries a portable device for a vehicle that functions as the mobile terminal 1.

  Generally, a vehicle travels at a slow speed in a parking lot. Therefore, the conditions regarding the vehicle speed included in the notification condition and the alarm condition are satisfied. Moreover, since the pedestrian who moves in a parking lot has a high possibility of being a user of a vehicle, the possibility that the portable device for vehicles as the portable terminal 1 is carried is high.

  In the parking lot, there are many areas that are blind spots for the driver of the automobile M due to other parked vehicles, and the user W1 may come out of the blind spots. However, according to the driving support system 100, when the user W1 is approaching the automobile M, the driving support apparatus 2 may be able to detect the approach of the pedestrian as an increase in reception intensity.

  As a result, the driving assistance device 2 can notify the driver that there is a moving body (in this case, the user W1) that is approaching. Upon receiving this notification, the driver can recognize that there is a moving body approaching the host vehicle M, and thus can take measures such as further reducing the vehicle speed or temporarily stopping the vehicle.

  That is, by making the vehicular portable device used in the keyless entry system or the like function as the mobile terminal 1, safety in a parking lot or the like can be improved. Note that when a vehicle portable device used in a keyless entry system or the like functions as the portable terminal 1, the vehicle portable device only needs to be provided with a switch for intermittently transmitting a radio signal.

  By the way, as other modes for detecting a moving body approaching the host vehicle M, various configurations using environment recognition devices such as a radar and a camera have been proposed. Even in such an aspect, it is possible to detect the presence of a moving body approaching the host vehicle M and notify the driver.

  However, the cost increases because an environment recognition device such as a radar or a camera is required. Moreover, it cannot detect a moving body approaching from a direction (so-called blind spot) where the environment recognition device cannot be detected.

  On the other hand, according to the above-described embodiment, an environment recognition device such as a radar or a camera is unnecessary, and the cost can be reduced. In particular, when a keyless entry system or the like is mounted on the automobile M, some of the facilities required by the driving support device 2 such as the wireless reception unit 22 can be realized using existing facilities. Therefore, when a keyless entry system or the like is mounted on the vehicle M, the cost for mounting the driving support device 2 on the vehicle M can be suppressed.

  Further, as yet another mode for detecting a moving body approaching the host vehicle M, a mode in which the mobile terminal sequentially transmits the current position with a radio signal is also assumed. According to such an aspect, the driving support device accumulates the position information including the received radio signal, and determines whether or not the transmission source is approaching the host vehicle from the time change of the position information. it can.

  However, in order to realize the assumed configuration, it is necessary to provide the mobile terminal with a device (for example, a GPS receiver) for detecting position information, which increases the manufacturing cost of the mobile terminal. In addition, the battery life is shortened because power is consumed to detect the position information. According to the configuration of the present embodiment for such a problem, a device for detecting position information is not necessary, and thus the cost required for manufacturing the mobile terminal 1 can be suppressed. In addition, the problem of power consumption can be alleviated.

  In addition, by installing a roadside device that transmits a radio signal that can be received by the radio reception unit 22 at an intersection to be temporarily stopped, it is possible to prompt the driver who passes through the intersection to pause. The reason is as follows. First, the reception intensity increases as the driver approaches the intersection to be paused at a speed less than the specified speed Vth. Therefore, approach notification information is output to the driver. When the driver tries to accelerate the host vehicle M in this state, an alarm is output as described above. The output of this alarm can prompt the driver to pause.

  On the other hand, when the driver temporarily stops the vehicle according to the approach notification information, the positional relationship between the roadside machine and the vehicle does not change, so that the reception intensity does not change. That is, the reception strength is not increasing. For this reason, the output of the approach warning information is stopped. No alarm is output even if the state is shifted to acceleration. That is, unnecessary alarm output is suppressed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, The following embodiment is also contained in the technical scope of this invention, and also the summary other than the following is also included. Various modifications can be made without departing from the scope.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to the drawings. Hereinafter, members having the same functions as those constituting the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted. In addition, when only a part of the configuration is mentioned, the first embodiment described above can be applied to the other parts.

  The main difference between the second embodiment and the previous first embodiment is the content of the radio signal transmitted by the mobile terminal 1. More specifically, in the first embodiment, the mobile terminal 1 only needs to transmit a radio signal having a frequency that can be received by the driving support device 2, and the signal needs to be a signal obtained by modulating specific data. There was no such thing.

  On the other hand, the mobile terminal 1 of the second embodiment is assigned a unique identification code (hereinafter referred to as a terminal ID) for identification with other mobile terminals 1, and each mobile terminal 1 It is assumed that a wireless signal including the terminal ID of the device is transmitted. The terminal ID only needs to be registered in the storage unit 12.

  In addition, the wireless reception unit 22 of the second embodiment performs predetermined signal processing such as demodulation, decoding, and error correction on the received signal, extracts data indicated by the received signal, and receives the received signal. This is provided to the vehicle-side control unit 21 in association with the strength. When the received signal is a signal transmitted from the mobile terminal 1, the data extracted from the received signal is the terminal ID of the mobile terminal 1 corresponding to the transmission source of the received signal.

  The reception intensity management unit F3 stores the reception intensity provided from the wireless reception unit 22 in association with the terminal ID indicating the transmission source of the received signal. The strength transition determination unit F4 determines whether or not the reception strength tends to increase for each terminal ID.

  The notification processing unit F6 is a case where the reception intensity corresponding to any one of the terminal IDs is determined to be increasing by the intensity transition determination unit F4, and the vehicle speed V is less than the specified speed Vth. If it is, the approach notification process is performed as in the first embodiment. Further, the alarm sound is output when the same alarm condition as in the first embodiment is satisfied.

  The operation and effect of the driving support system 100 in the second embodiment will be described with reference to FIGS. FIG. 7 shows a situation where users W2 and W3 as pedestrians carrying the mobile terminal 1 are present around the host vehicle M, respectively. The user W2 is moving in a direction approaching the host vehicle M, and the user W3 is moving in a direction moving away from the host vehicle M. For convenience, the periphery of the host vehicle M here refers to a range in which a radio signal transmitted from the mobile terminal 1 can be received.

  In such a case, the driving support device 2 alternately receives a radio signal transmitted from the mobile terminal 1 carried by the user W2 and a radio signal transmitted from the mobile terminal 1 carried by the user W3. To do. As a result, the reception intensity detection unit 221 transmits the reception intensity of the radio signal transmitted from the mobile terminal 1 carried by the user W2 and the mobile terminal 1 carried by the user W3, as shown in FIG. The received intensity of the received radio signal is alternately output.

  Thus, in a situation where wireless signals from a plurality of portable terminals 1 are received, it is detected from the simple time change of the reception intensity output from the reception intensity detection unit 221 that there is a user W2 that is approaching. It becomes difficult to do.

  In response to this problem, according to the configuration of the second embodiment, the reception intensity provided by the reception intensity detection unit 221 is stored in the RAM 212 by the reception intensity management unit F3 by distinguishing it for each terminal ID. Conceptually, the temporal change in reception strength shown in FIG. 8 is distinguished for each transmission source as shown in FIG. 9A shows the time change of the reception intensity from the mobile terminal 1 of the user W2, and FIG. 9B shows the time change of the reception intensity from the mobile terminal 1 of the user W3.

  According to such an aspect, the strength transition determination unit F4 is a case where there are a plurality of portable terminals 1 around the host vehicle M, and it is not possible to determine whether or not the reception strength tends to increase as a whole. However, it is possible to detect the presence of the mobile terminal 1 whose reception intensity tends to increase. That is, according to the present embodiment, it is possible to present approach notification information to the driver and to output an alarm sound with higher accuracy than in the first embodiment.

[Modification 1]
When the reception intensity provided from the reception intensity detection unit 221 is a saturation level corresponding to the upper limit of the range of reception intensity that can be detected by the reception intensity detection unit 221, the notification processing unit F 6 receives a strong radio wave. Information indicating that this is being performed may be displayed on the display 24. In other words, the range of the reception intensity that can be detected by the reception intensity detection unit 221 corresponds to the range that the output value of the reception intensity detection unit 221 can take.

  The case where the reception intensity is at a saturation level is a situation where a very strong radio wave is received. Therefore, even when a radio signal transmitted from the mobile terminal 1 is actually received, there is a possibility that the radio signal transmitted from the mobile terminal 1 is erased by the strong radio wave.

  That is, when the reception intensity is at the saturation level, it can be determined whether or not the reception intensity tends to increase, which corresponds to the determination of whether or not there is a user approaching the host vehicle M. There is a fear that it is gone.

  For this reason, when the reception intensity is at a saturation level, the notification processing unit F6 displays information indicating that a strong radio wave is received on the display 24, so that the reception intensity tends to increase for the driver. It can be notified that the determination of whether or not there is a failure. Moreover, according to such an aspect, the driver can be indirectly recognized that there may be an approaching user.

  As another aspect, the notification processing unit F6 cannot determine whether there is a user approaching the host vehicle M as a result of receiving a strong radio wave when the reception intensity is at a saturation level. Visual information indicating the situation may be output. Here, the visual information refers to information shown in a manner visually perceivable by the driver. Specifically, display on the display 24 and lighting or blinking of an indicator.

  In addition, the value set as the saturation level in Modification 1 does not have to be the upper limit value of the reception intensity range that the reception intensity detection unit 221 can detect. A value obtained by multiplying the upper limit value of the reception intensity range that can be detected by the reception intensity detection unit 221 by a predetermined coefficient less than 1 such as 0.9 or 0.8 may be used. That is, the range of values regarded as the saturation level may be a range of values sufficiently larger than the range that can be observed as the reception intensity of the radio signal transmitted from the mobile terminal 1. Note that the case where the reception intensity reaches the saturation level is assumed, for example, when the host vehicle M is traveling near the radio tower.

[Modification 2]
In 2nd Embodiment, the portable terminal 1 and the driving assistance device 2 may be the structure which can implement bidirectional | two-way communication by directly transmitting / receiving a radio signal (this is set as the modification 2).

  Specifically, as illustrated in FIG. 10, the mobile terminal 1 includes a receiving unit (hereinafter, mobile-side receiving unit) 15 that receives a signal in a frequency band used for wireless communication with the driving support device 2. . The driving support device 2 includes a transmission unit (hereinafter, vehicle-side transmission unit) 30 that transmits a signal in a frequency band that can be received by the mobile terminal 1.

  In FIG. 10, a part of members included in the mobile terminal 1 such as the storage unit 12 and a part of members included in the driving support device 2 such as the speaker 23 are not illustrated. In FIG. 10, the wireless transmission unit 13 and the mobile-side reception unit 15 each have a different antenna, but the wireless transmission unit 13 and the mobile-side reception unit 15 may share an antenna. Similarly, the wireless reception unit 22 and the vehicle-side transmission unit 30 may share an antenna.

  It is preferable that the driving support device 2 and the mobile terminal 1 in the second modification are configured as follows. That is, in the driving support device 2, when the strength transition determination unit F4 determines that there is the mobile terminal 1 whose reception strength tends to increase, the vehicle-side transmission unit 30 has a tendency that the reception strength increases. A signal indicating that the vehicle is approaching the host vehicle M (hereinafter referred to as an approach notification signal) is transmitted to the mobile terminal 1.

  When the mobile-side receiving unit 15 receives the approach notification signal, the mobile-side control unit 11 vibrates a vibrator (not shown) or outputs an alarm sound from a speed (not shown) so that an approaching vehicle Notify the user that it exists.

  According to such an aspect, not only the driver of the automobile M but also the user of the mobile terminal 1 can recognize the presence of the host vehicle M.

[Modification 3]
Although the aspect which made the mobile body side apparatus as described in the claim the portable terminal 1 carried by the user was illustrated above, it is not restricted to this. The mobile unit side device may be a device mounted on a bicycle (hereinafter, a bicycle terminal). The bicycle terminal as the mobile unit side device only needs to have the same function as the mobile terminal 1 described above. The power source 14 provided in the bicycle terminal as the mobile unit side device may be realized by using a hub dynamo that generates power by rotating the hub of the bicycle on which the bicycle terminal is mounted.

DESCRIPTION OF SYMBOLS 100 Driving assistance system, 1 Portable terminal (mobile body side apparatus), 2 Driving assistance apparatus, 11 Portable side control part, 12 Storage part, 13 Wireless transmission part, 14 Power supply, 21 Vehicle side control part, 22 Wireless reception part, 23 Speaker , 24 display, 25 ignition switch, 26 accelerator sensor, 27 brake sensor, 28 vehicle speed sensor, 29 shift position sensor, F1 vehicle information acquisition unit, F11 vehicle speed acquisition unit, F2 communication control unit, F3 reception intensity management unit (reception intensity acquisition unit) Part), F4 intensity transition judgment part, F5 acceleration operation judgment part, F6 notification processing part (notification part)

Claims (9)

A driving support system comprising: a driving support device (2) used in an automobile; and a mobile body side device (1) mounted or carried on a mobile body existing outside the automobile where the driving support device is used. ,
The mobile body side device is:
A transmitter (13) that transmits a radio signal in a pre-assigned frequency band intermittently or continuously;
The driving support device includes:
A receiver (22) for receiving a radio signal in the frequency band;
A reception strength acquisition unit (F3) that acquires a reception strength that is a signal strength of a radio signal received by the reception unit;
An intensity transition determination unit (F4) that determines whether or not the reception intensity acquired by the reception intensity acquisition unit tends to increase;
A vehicle speed acquisition unit (F11) for sequentially acquiring the current vehicle speed of the automobile;
A notification unit (F6) that outputs information for notifying a driver of the vehicle about a moving body existing around the vehicle;
The notification unit is configured such that the vehicle speed acquired by the vehicle speed acquisition unit is less than a specified speed corresponding to an upper limit of a speed that can be regarded as a slowing speed, and the reception intensity is increased by the intensity transition determination unit. When it is determined that the vehicle is in a tendency, the driving support system outputs information indicating that the moving body approaching the vehicle is present. In claim 1,
The said notification part outputs the information which shows that the said mobile body approaching the said vehicle exists in the aspect which the said driver can visually perceive, The driving assistance system characterized by the above-mentioned. In claim 2,
The notification unit is approaching the automobile while the vehicle speed is less than the specified speed and the state in which the reception intensity is determined to be increasing by the intensity transition determination unit continues. A driving support system, characterized in that it continues to output information indicating that the mobile body is present. In claim 2 or 3,
An acceleration operation determination unit (F5) for determining whether or not the driver has performed an acceleration operation;
In the state where the vehicle speed acquired by the vehicle speed acquisition unit is less than the specified speed and the reception intensity is determined to increase by the intensity transition determination unit, the notification unit A driving support system that outputs an alarm when it is determined by the operation determination unit that the acceleration operation has been performed. In any one of Claims 1-4,
The notification unit indicates that a strong radio wave is received when the reception intensity acquired by the reception intensity acquisition unit is at a saturation level corresponding to an upper limit value that can be taken as the reception intensity. The driver can visually perceive information or information indicating that it is not possible to determine whether or not there is the moving object approaching the automobile as a result of receiving strong radio waves. A driving support system characterized in that the output is performed in a manner. In any one of Claim 1 to 5,
A plurality of the mobile body side devices exist,
Each of the plurality of mobile body side devices is set with a unique identification code for distinguishing from the other mobile body side devices,
The transmitter transmits a radio signal indicating the identification code set in the mobile unit side device;
The reception strength acquisition unit distinguishes and stores the reception strength of the radio signal received by the reception unit for each identification code indicated in the radio signal,
The driving support system, wherein the intensity transition determination unit determines, for each identification code, whether or not the reception intensity associated with the identification code tends to increase. In any one of Claim 1 to 6,
The automobile is automatically compatible with a vehicle electronic key system that controls locking / unlocking of the door of the automobile based on reception of a radio signal transmitted from a vehicle portable device associated with the automobile. A four-wheeled vehicle
The driving support system, wherein the receiving unit is realized by using a receiving device for receiving a radio signal transmitted from the vehicular portable device, provided in the vehicular electronic key system. In claim 7,
The driving support system, wherein the mobile device is the portable device for a vehicle used in the electronic key system for a vehicle. A driving support device including a notification unit (F6) that is used in an automobile and outputs information for notifying a driver of the automobile about a moving body existing around the automobile,
A receiving unit (22) for receiving a radio signal transmitted from a mobile unit device mounted on or carried by a mobile unit existing outside the automobile;
A reception strength acquisition unit (F3) that acquires a reception strength that is a signal strength of a radio signal received by the reception unit;
An intensity transition determination unit (F4) that determines whether or not the reception intensity acquired by the reception intensity acquisition unit tends to increase;
A vehicle speed acquisition unit (F11) for sequentially acquiring the current vehicle speed of the automobile;
A notification unit (F6) that outputs information for notifying the driver about a moving body existing around the vehicle;
The notification unit is configured such that the vehicle speed acquired by the vehicle speed acquisition unit is less than a specified speed corresponding to an upper limit of a speed that can be regarded as a slowing speed, and the reception intensity is increased by the intensity transition determination unit. When it is determined that the vehicle is in a tendency, the driving support device outputs information indicating that the moving body that is approaching the vehicle is present.

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