Vehicles equipped with a smart key system

Abstract

To provide a vehicle with a smart key system capable of suppressing deterioration of original running performance of a vehicle.SOLUTION: A vehicle 100 includes a travel control device 40 that controls travel of the vehicle 100. A vehicle-mounted device 20 includes a vehicle-mounted communication device 22 having a vehicle-mounted transmitter 22A that transmits a search signal for searching a portable device 30 with a predetermined radio wave intensity, and a communication control device 21 that controls communication of the vehicle-mounted communication device 22. The vehicle-mounted device 20 or the portable device 30 includes operation switches 23 and 33 for starting or stopping a main power supply 41 of the travel control device 40. The communication control device 21 controls the vehicle-mounted transmitter 22A to implement a limit to reduce or zero the search radio wave intensity transmitted from the vehicle-mounted transmitter 22A at least until the vehicle 100 starts running after the main power supply 41 of the travel control device 40 is activated by the operation switches 23 and 33.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle having a smart key system. [Background technology]

[0002] As an example of this type of technology, Patent Document 1 discloses a smart key system that includes an onboard device mounted in a vehicle and a portable device (smart key) capable of wireless communication with the onboard device. The onboard device of the smart key system has an onboard transmitter that transmits a search signal to search for the portable device, and limits the search radio wave intensity of the search signal to zero while the vehicle is moving. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-183988 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the vehicle shown in Patent Document 1, the on-board transmitter limits the search radio wave intensity of the search signal to zero while the vehicle is traveling, thereby reducing the power consumption of the on-board transmitter. However, if the on-board transmitter transmits a search signal with a normal strong search radio wave intensity from the start of the main power supply of the vehicle's travel control device until at least the start of the vehicle's travel, it is expected that the strong search radio wave intensity of this search signal will increase the electrostatic potential of the vehicle. At least until the vehicle starts traveling, such electrostatic charging may prevent the vehicle from performing its original travel performance.

[0005] An object of the present invention is to provide a vehicle having a smart key system that prevents the vehicle's original driving performance from being impaired by a search signal of strong search radio wave strength that searches for a portable unit. [Means for solving the problem]

[0006] In consideration of the above problem, the vehicle of the invention is a vehicle having a smart key system including an onboard unit and a portable unit capable of wireless communication with the onboard unit, wherein the vehicle is equipped with a driving control device that controls the driving of the vehicle, the onboard unit is equipped with an onboard communication unit having an onboard transmitter that emits a search signal for searching for the portable unit at a predetermined search radio wave strength, and a communication control unit that controls communication of the onboard communication unit, and at least one of the onboard unit or the portable unit is equipped with an operation switch that starts or stops the main power supply of the driving control unit, and the communication control unit controls the onboard transmitter to execute a restriction to reduce or set to zero the search radio wave strength emitted from the onboard transmitter from the time the main power supply is started by the operation switch at least until the vehicle starts driving.

[0007] According to the present invention, when the in-vehicle transmitter transmits a search signal for searching for the portable device with a predetermined search radio wave intensity, the portable device receives the search signal and transmits a location information signal to the in-vehicle device, which enables the location of the portable device to be specified. As a result, the in-vehicle device can specify the location of the portable device relative to the vehicle.

[0008] Here, at least one of the in-vehicle device and the portable device is equipped with an operation switch, and the driving control device can be started or stopped by operating the operation switch. According to the present invention, by operating the operation switch, a restriction is executed to reduce or zero the search radio wave intensity transmitted from the in-vehicle transmitter from the time the main power supply of the driving control device is started until at least the vehicle starts traveling. This makes it possible to suppress an increase in the electrostatic charge potential of the vehicle caused by a search signal with a strong search radio wave intensity from the in-vehicle transmitter.

[0009] Here, as long as the charging of the vehicle is suppressed by the restriction of reducing or setting to zero the search radio wave intensity of the search signal transmitted from the vehicle-mounted transmitter, the timing of ending the restriction is not particularly limited. In a more preferred embodiment, the communication control device controls the vehicle-mounted transmitter so as to execute the restriction of reducing or setting to zero the search radio wave intensity transmitted from the vehicle-mounted transmitter during the period from when the main power source is started to when the main power source is stopped.

[0010] In this aspect, the restriction of reducing or setting to zero the search radio wave intensity of the search signal transmitted from the in-vehicle transmitter is executed from the time the main power supply of the driving control device is started until at least the vehicle starts to drive, while the vehicle is driving, and after the vehicle stops driving and until the main power supply of the driving control device is stopped, so that the restriction of reducing or setting to zero the search radio wave intensity of the search signal is executed before the vehicle starts, while the vehicle is driving, and after the vehicle is stopped. Therefore, in this embodiment, before the vehicle starts (including restarting after stopping) and while the vehicle is driving, the restriction of reducing or setting to zero the search radio wave intensity can prevent the vehicle from being charged.

[0011] In another preferred embodiment, a static eliminator for eliminating static electricity charged to the vehicle is disposed on the surface of the vehicle. In this embodiment, for example, the static electricity charged to the vehicle can be discharged into the atmosphere by an air ionization self-discharge type static eliminator described in Japanese Patent No. 6168157.

[0012] In a more preferred embodiment, the vehicle has a sliding mechanism that slides via a lubricant, and the lubricant may contain conductive particles that neutralize the static electricity stored in the sliding mechanism, thereby making it possible to further neutralize the static electricity stored in the sliding mechanism via the conductive particles of the lubricant.

[0013] Here, in a more preferred embodiment, the vehicle-mounted unit is equipped with a detection device that detects the open / closed state of the trunk or door of the vehicle, and the communication control device controls the vehicle-mounted transmitter to lift the restriction on reducing or setting to zero the search radio wave strength while the detection device detects that the trunk or door is open.

[0014] Here, for example, after the driving control device is started, if a vehicle occupant carrying a portable device opens the door or trunk while the vehicle is stopped, it is assumed that the position of the portable device cannot be searched for. Therefore, in this embodiment, when the door or trunk is open, the restriction on reducing or setting to zero the search radio wave strength of the search signal is lifted, and the radio wave strength of the search signal is restored. This allows the in-vehicle device to search for the portable device even if the portable device is taken out of the vehicle.

[0015] In another preferred embodiment, the portable unit has a portable communication unit that receives the search signal from the vehicle-mounted transmitter and transmits a location information signal of the portable unit to the vehicle-mounted unit, and the communication control device determines whether the portable unit is inside or outside the vehicle based on the location information signal, and controls the vehicle-mounted transmitter to lift the restriction on reducing or setting the search radio wave strength to zero if the portable unit is outside the vehicle.

[0016] Here, for example, if the portable device is taken out of the vehicle while the main power supply of the driving control device is activated, and further, if the main power supply of the driving control device is activated remotely from outside the vehicle by an operation switch of the portable device, it is assumed that the position of the portable device outside the vehicle cannot be searched for if the restriction of lowering or setting to zero the search radio wave intensity is executed. Therefore, in this aspect, when the portable device is outside the vehicle, the restriction of lowering or setting to zero the search radio wave intensity of the search signal is lifted, so that the in-vehicle device can cause the portable communication unit of the portable device to receive the search signal and receive the position information signal from the portable communication unit. This allows the in-vehicle device to grasp the position of the portable device outside the vehicle.

[0017] In a further preferred embodiment, the portable device has the operation switch, and the portable communication device transmits a request signal for starting and stopping the main power supply by operating the operation switch of the portable device, and the portable communication device executes a restriction to reduce or zero the radio wave strength of the location information signal transmitted from the portable communication device in accordance with a restriction to reduce or zero the search radio wave strength of the vehicle-mounted transmitter.

[0018] According to this aspect, the portable communication device executes a restriction to reduce or zero the radio wave strength of a location information signal (location information search signal) with strong radio wave strength transmitted from the portable communication device in response to a restriction to reduce or zero the strong search radio wave strength of the search signal from the vehicle-mounted transmitter, thereby suppressing an increase in the static electricity potential that is charged to the vehicle due to the location information signal. Effect of the Invention

[0019] According to the present invention, at least until the vehicle starts traveling, a search signal with a strong search radio wave strength that searches for a portable unit can be used to prevent the electrostatic charge potential of the vehicle from increasing and the vehicle's original traveling performance from being impaired. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic conceptual diagram of a vehicle having a smart key system according to a first embodiment of the present invention. [Diagram 2] 2 is a control block diagram of the communication control device shown in FIG. [Diagram 3] 3 is a control flow diagram performed by the communication control device shown in FIG. 2. [Figure 4] FIG. 11 is a block diagram of a communication control device according to a second embodiment. [Diagram 5] 5 is a control flow diagram performed by the communication control device shown in FIG. [Figure 6] FIG. 11 is a block diagram of a communication control device according to a third embodiment. [Figure 7]6 is a control flow diagram performed by the communication control device shown in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, vehicles having smart key systems according to some embodiments of the present invention will be described with reference to the drawings.

[0022] [First embodiment] Fig. 1 is a schematic conceptual diagram of a vehicle 100 according to a first embodiment of the present invention. As shown in Fig. 1, the vehicle 100 according to this embodiment has a smart key system 1. The vehicle 100 may be any of a gasoline vehicle, a hybrid vehicle, an electric vehicle, and a fuel cell vehicle, and is not particularly limited as long as the smart key system 1 can be used.

[0023] The vehicle 100 further includes a driving control device 40 that controls the driving of the vehicle 100, and a main power source 41 that supplies power to the driving control device 40. As will be described later, the driving control device 40 supplies power to a power source (not shown) of the vehicle 100 such as an engine or a drive motor, and controls devices that are the power sources.

[0024] In this embodiment, the smart key system 1 includes an on-board device 20 mounted on a vehicle 100, and a portable device 30 capable of wireless communication with the on-board device 20. The smart key system 1 is a system in which, by operating an operation switch or the like on the portable device 30 outside the vehicle, a door 102 of the on-board device 20 is locked or unlocked, and a main power source 41 of a driving control device 40 (described later) is started (started) and stopped via the on-board device 20. The on-board device 20 includes an on-board communication device 22 that communicates with the portable device 30 and devices outside the vehicle 100, and a communication control device 21 that controls communication of the on-board communication device 22.

[0025] The driving control device 40 is started by power being supplied from the main power source 41 by at least one of the operation switches 23 and 33 described later. The detailed operation of starting and stopping the main power source 41 of the driving control device 40 will be described later.

[0026] When the main power supply 41 of the driving control device 40 is started, the driving control device 40 controls the driving of the vehicle 100 in response to the driver's operation of a shift lever (not shown), an accelerator pedal (not shown), a steering wheel (not shown), and a brake (not shown). Note that the driving control of the vehicle 100 is generally known in the various vehicles mentioned above, and therefore a detailed description thereof will be omitted.

[0027] The in-vehicle communication device 22 includes an in-vehicle transmitter 22A that transmits a search signal for searching for the portable device 30 at a predetermined search radio wave intensity, and an in-vehicle receiver 22B that receives the location information signal transmitted from the portable device 30.

[0028] In this embodiment, the transmission of the search signal from the in-vehicle transmitter 22A is performed by the communication control device 21, without being linked to the start or stop of the main power supply 41 of the driving control device 40. In this embodiment, the in-vehicle transmitter 22A may be provided with a detection device for detecting radio waves that become noise with respect to the search radio wave strength of the search signal. In this case, the communication control device 21 may control the in-vehicle transmitter 22A so that the search radio wave strength of the search signal is increased according to the intensity of the detected radio waves that become noise. However, even if the detection device for detecting radio waves that become noise detects radio waves, when a condition for limiting the search radio wave strength of the search signal, which will be described later, is established, the communication control device 21 does not control the in-vehicle transmitter 22A that increases the search radio wave strength, and prioritizes the restriction of reducing or setting to zero the search radio wave strength of the search signal.

[0029] The portable device 30 is a so-called smart key, and is a device that can be carried by the driver, etc. The portable device 30 has a portable communication device 32 that receives a search signal from the in-vehicle transmitter 22A and transmits a location information signal of the portable device 30 to the in-vehicle device 20. Specifically, the portable communication device 32 includes a portable transmitter 32A and a portable receiver 32B.

[0030] The portable transmitter 32A transmits a position information signal of the portable device 30, and a request signal for starting or stopping a main power source 41 of a driving control device 40 of the vehicle 100, which will be described later, and the like. In addition, if the portable device 30 has a request switch (operation switch) for requesting an operation of the vehicle 100, such as locking or unlocking the door 102 of the vehicle 100, the portable transmitter 32A transmits a request signal according to the request switch. The portable receiver 32B receives a search signal and the like from the in-vehicle transmitter 22A.

[0031] Here, the location information signal transmitted by the portable transmitter 32A may be, for example, an electromagnetic wave with a specific wavelength that identifies the portable device 30, and the relative position with respect to the portable device 30 may be identified by detecting the intensity and direction of this electromagnetic wave with the in-vehicle receiver 22B. The location information signal transmitted by the portable transmitter 32A may be, for example, a signal related to latitude and longitude obtained by a GPS system (not shown) mounted on the portable device 30. The portable device 30 may be, for example, a mobile terminal such as a tablet or a smartphone. In this way, the location information signal transmitted by the portable transmitter 32A is not particularly limited as long as it can transmit a signal that can identify the location information of the portable device 30.

[0032] In this way, when the in-vehicle transmitter 22A transmits a search signal for searching the portable device 30 at a predetermined search radio wave intensity, the portable transmitter 32A receives the search signal and transmits a location information signal that enables identification of the location of the portable device 30 to the in-vehicle device 20. The in-vehicle device 20 can identify the location of the portable device 30 relative to the vehicle 100 using the communication control device 21 described later, based on the location information signal received by the in-vehicle receiver 22B.

[0033] In this embodiment, the in-vehicle device 20 and the portable device 30 each have an operation switch 23, 33 for starting or stopping the main power supply 41 of the driving control device 40. The operation switches 23, 33 are switches operated by an operator.

[0034] When operated to start or stop, the operation switch 23 of the in-vehicle device 20 transmits a request signal (start / stop signal) for starting or stopping the main power supply 41 of the driving control device 40 to a main power supply on relay (not shown) of the driving control device 40 or the like. When operated to start or stop, the operation switch 33 of the portable device 30 transmits a request signal (start / stop signal) for starting or stopping the main power supply 41 of the driving control device 40 to a main power supply on relay (not shown) of the driving control device 40 or the like via the portable transmitter 32A and the in-vehicle receiver 22B.

[0035] As a result, the main power supply 41 of the driving control device 40 is started and stopped by the start or stop request signal of the operation switches 23, 33, and the main power supply 41 can supply and cut off power to the driving control device 40. This makes it possible to start and stop the driving control device 40. Note that, in this embodiment, the operation switch 23 of the in-vehicle device 20 and the operation switch 33 of the portable device 30 are provided, but an operation switch may be provided only on either the in-vehicle device 20 or the portable device 30 as long as the driving control device 40 can be started and stopped.

[0036] Here, if the vehicle 100 is, for example, a gasoline vehicle, the engine (not shown) serving as the power source starts when the main power source 41 of the cruise control device 40 is started. If the vehicle 100 is, for example, an electric vehicle, a hybrid vehicle, or a vehicle equipped with a fuel cell, the start of the main power source 41 of the cruise control device 40 puts a drive motor (not shown) for driving the vehicle into a driveable state. For example, if the vehicle 100 is a vehicle equipped with a fuel cell, the start of the main power source 41 of the cruise control device 40 may start power generation in the fuel cell (not shown), and the drive motor (not shown) for driving the vehicle into a driveable state.

[0037] In this embodiment, the vehicle-mounted device 20 includes a detector 25 that detects the open / closed state of the trunk 101 or the door 102 of the vehicle 100. A signal indicating the open / closed state of the trunk 101 and the door 102 detected by the detector 25 is transmitted to the communication control device 21. Furthermore, in this embodiment, as shown in FIG. 1, a static eliminator 50 that eliminates static electricity charged to the vehicle 100 is disposed on the surface of the vehicle 100. This allows the static electricity charged to the vehicle 100 to be discharged into the atmosphere. In addition, the vehicle 100 has a sliding mechanism 105 such as a differential that slides via a lubricant, and conductive particles that eliminate the electricity charged to the sliding mechanism 105 are added to the lubricant. The static electricity charged to the sliding mechanism 105 can be further eliminated via the conductive particles of the lubricant.

[0038] The main power supply 41 of the driving control device 40 is started and stopped by the operation switches 23, 33, but in this embodiment, the power supply of the communication control device 21 is maintained in the ON state regardless of the start and stop of the main power supply 41 of the driving control device 40. Note that, although the driving control device 40 and the communication control device 21 are separate devices in this embodiment, the driving control device 40 and the communication control device 21 may be integrated into one control device.

[0039] The communication control device 21 includes a calculation device for executing control of the in-vehicle communication device 22 and a storage device for storing programs for these controls. The communication control device 21 includes, as software, a control program for the search radio wave intensity of the search signal of the in-vehicle transmitter 22A.

[0040] 2 is a control block diagram for controlling the search radio wave intensity of the search signal transmitted by the vehicle-mounted transmitter 22A. Note that the control block diagram and the like related to the driving control are not particularly limited, and therefore detailed description thereof will be omitted.

[0041] The communication control device 21 controls the in-vehicle transmitter 22A to implement a restriction to reduce or set to zero the search radio wave intensity of the search signal transmitted from the in-vehicle transmitter 22A from the time the main power supply 41 of the driving control device 40 is started by the operation switches 23, 33 until at least the time the vehicle 100 starts traveling. In this embodiment, the communication control device 21 implements a restriction to reduce or set to zero the search radio wave intensity of the search signal transmitted from the in-vehicle transmitter 22A from the time the main power supply 41 of the driving control device 40 is started until the main power supply 41 of the driving control device 40 is stopped.

[0042] Specifically, as shown in FIG. 2, the communication control device 21 includes a start / stop determination unit 21A, a strength restriction unit 21B, and a restriction removal unit 21C.

[0043] The start / stop determination unit 21A determines whether the main power supply 41 is started or stopped based on the start / stop signal of the driving control device 40 or the start / stop signal of the operation switch 33 of the portable device 30 or the operation switch 23 of the in-vehicle device 20 via the in-vehicle receiver 22B. For example, the start / stop determination unit 21A determines that the driving control device 40 has started or stopped by receiving the start signal and the stop signal after the driving control device 40 has started or stopped. In this case, since the main power supply 41 of the driving control device 40 is determined to have started or stopped by the substantial start / stop of the driving control device 40, it is possible to avoid erroneous determination of the start / stop of the main power supply 41 of the driving control device 40. In particular, if the main power supply 41 of the driving control device 40 is erroneously determined to have stopped, the restriction on the search radio wave intensity of the search signal is released, which may cause static electricity to be generated in the vehicle 100. Therefore, it is preferable that the start / stop determination unit 21A determines that the main power supply 41 of the driving control device 40 is stopped by receiving a stop signal from the driving control device 40.

[0044] The intensity limiting unit 21B receives the determination result of the activation / deactivation determination unit 21A regarding the activation of the main power supply 41 of the driving control device 40, and transmits a control signal to the in-vehicle transmitter 22A to limit the search radio wave intensity of the search signal. Note that before the intensity limiting unit 21B performs the restriction, the in-vehicle transmitter 22A transmits the search signal at a search radio wave intensity (a preset strong search radio wave intensity) of the search signal that can search for the portable device 30 inside the vehicle.

[0045] The intensity limiting unit 21B limits the search radio wave intensity of the search signal to, for example, zero, or limits the search radio wave intensity to a level lower than a preset search radio wave intensity. The low radio wave intensity here may be an intensity at which the search signal cannot search for the portable device 30 inside the vehicle. In this embodiment, the intensity limiting unit 21B can execute a restriction to lower or set to zero the search radio wave intensity transmitted from the vehicle-mounted transmitter by controlling an adjustment unit (not shown) that adjusts the search radio wave intensity mounted on the vehicle-mounted transmitter 22A.

[0046] The restriction release unit 21C releases the restriction on the search radio wave strength of the search signal by the strength limiter 21B, in other words, restores the search radio wave strength limited by the strength limiter 21B to the original strength. In this embodiment, the timing of this release is based on either a stop signal of the driving control device 40 or a stop signal of the operation switch 33 of the portable device 30 or the operation switch 23 of the in-vehicle device 20 via the in-vehicle receiver 22B. Preferably, upon receiving a determination result by the start / stop determination unit 21A that the driving control device 40 has stopped, the restriction release unit 21C causes the strength limiter 21B to release the restriction on the search radio wave strength of the search signal.

[0047] The control flow of the smart key system 1 according to this embodiment will be described below with reference to Fig. 3. First, before step S31, the vehicle 100 is in a parked state. In this state, a search signal is transmitted from the in-vehicle transmitter 22A of the in-vehicle device 20 at a specific search radio wave intensity, and the main power supply 41 of the driving control device 40 is stopped.

[0048] Next, in step S32, the start / stop determination unit 21A determines whether to start the driving control device 40. In step S32, if it is determined that the main power supply 41 of the driving control device 40 will be started by the request signal (or has already started) (YES), the process proceeds to step S33, where the intensity limiting unit 21B limits the strong search radio wave intensity of the search signal transmitted from the in-vehicle transmitter 22A. On the other hand, if the main power supply 41 of the driving control device 40 has not started (NO), the process returns to step S31, where the in-vehicle transmitter 22A continues transmitting the search signal at a preset strong search radio wave intensity.

[0049] Next, in step S34, the start / stop determination unit 21A determines whether to stop the main power supply 41 of the driving control device 40. If it is determined in step S34 that the main power supply 41 of the driving control device 40 will be stopped by the request signal (or has already been stopped) (YES), the process proceeds to step S35, where the restriction release unit 21C causes the intensity limiter 21B to release the restriction on the searching radio wave strength of the search signal. On the other hand, if it is determined in step S34 that the main power supply 41 of the driving control device 40 will not be stopped (NO), the process returns to step S33, and the intensity limiter 21B continues to limit the searching radio wave strength of the search signal transmitted from the in-vehicle transmitter 22A.

[0050] According to this embodiment, from when the main power supply 41 of the driving control device 40 is started (specifically, from when the start-up is determined) until at least when the vehicle 100 starts driving, the communication control device 21 limits the strong search radio wave intensity of the search signal for location information from the in-vehicle transmitter 22A. This makes it possible to suppress an increase in the electrostatic potential of the vehicle due to a search signal with a strong search radio wave intensity from the in-vehicle transmitter 22A.

[0051] Particularly in this embodiment, from when the main power supply 41 of the driving control device 40 is started (specifically, from when it is determined that the power supply 41 is started) until when the main power supply 41 of the driving control device 40 is stopped (specifically, until it is determined that the power supply 41 is stopped), the strong search radio wave intensity of the search signal for location information transmitted from the in-vehicle transmitter 22A is limited. Therefore, from step S33 to step S34, even in the state before the vehicle 100 starts, when the vehicle is traveling, and after the vehicle is stopped, the search radio wave intensity of the search signal is limited. Therefore, in this embodiment, before the vehicle 100 starts (including restarting from a stop) and while the vehicle 100 is traveling, the vehicle can be prevented from being charged by the strong radio waves of the location information search signal, and the original driving performance of the vehicle can be prevented from being impaired.

[0052] Second Embodiment The vehicle 100 according to the second embodiment will be described below. The difference from the first embodiment is that the limit on the search radio wave intensity of the search signal is changed depending on the open / closed state of the trunk 101 and the door 102 of the vehicle 100. Therefore, only the difference from the first embodiment will be described below with reference to Figs. 4 and 5.

[0053] In this embodiment, as shown in Fig. 4, a detection signal from a detection device 25 (see Fig. 1) is input to the communication control device 21. The detection device 25 detects the open / closed states of the trunk 101 and the door 102 of the vehicle 100. In this embodiment, the communication control device 21 releases the restriction on reducing or setting to zero the search radio wave intensity of the search signal while the detection device 25 detects that the trunk 101 or the door 102 is open.

[0054] Specifically, in this embodiment, the communication control device 21 includes an open / closed determination unit 21D in addition to the configuration of the first embodiment. The open / closed determination unit 21D determines whether the trunk 101 or the door 102 is open by the detection device 25. The open / closed determination unit 21D determines the open / closed state of the trunk 101 or the door 102 at regular intervals (several milliseconds) and transmits the determination result to the restriction release unit 21C.

[0055] When the strength limiting unit 21B limits the search radio wave strength of the search signal to be reduced or set to zero and the open / closed determination unit 21D determines that the trunk 101 or the door 102 is open, the restriction lifting unit 21C lifts the restriction on the search radio wave strength by the strength limiting unit 21B. On the other hand, when the open / closed determination unit 21D determines that the trunk 101 or the door 102 is closed, the restriction lifting unit 21C continues the restriction on the radio wave strength by the strength limiting unit 21B.

[0056] The control flow of the smart key system 1 according to this embodiment will be described below with reference to Fig. 5. Steps S31 to S33 are the same as those in the first embodiment. Next, in step S51, the open / close determination unit 21D determines whether the trunk 101 or the door 102 is open.

[0057] If it is determined that the trunk 101 or the door 102 is not open (NO), the trunk 101 and the door 102 are both closed, so the process proceeds to step S52, and the restriction on the search radio wave intensity is continued as in the first embodiment. On the other hand, if it is determined that either the trunk 101 or the door 102 is open (YES), the process proceeds to step S35, and the restriction on the search radio wave intensity by the restriction removal unit 21C is lifted. Note that in steps S34 and S35, the same control as in the first embodiment is performed.

[0058] According to this embodiment, for example, after the main power supply 41 of the driving control device 40 is started, while the vehicle 100 is stopped, a passenger of the vehicle 100 may open the trunk 101 or the door 102 while carrying the portable device 30. In such a case, in step S35, the restriction release unit 21C releases the restriction on the search radio wave strength of the search signal, thereby restoring the search radio wave strength of the search signal to the original radio wave strength.

[0059] This allows the portable device 30 to be searched for even if the portable device 30 is taken out of the vehicle. Note that, in a state where the trunk 101 or the doors 102 of the vehicle 100 are all closed, the restriction of the search radio wave intensity by the intensity restriction unit 21B continues in step S52, so that the same effect as in the first embodiment is achieved.

[0060] Third Embodiment A vehicle 100 according to the third embodiment will be described below. The difference from the second embodiment is that the limit on the search radio wave intensity of the search signal is changed depending on whether the portable device 30 is outside or inside the vehicle. Therefore, only the difference from the second embodiment will be described below with reference to Figs. 6 and 7. Note that the configuration that constitutes this difference may be applied to the first embodiment.

[0061] As in the first embodiment, in this embodiment, the portable communication unit 32 of the portable device 30 receives a search signal from the vehicle-mounted transmitter 22A and transmits a location information signal of the portable device 30 to the vehicle-mounted device 20, as described above.

[0062] In this embodiment, as shown in Fig. 6, the communication control device 21 further includes a position calculation unit 21F and a position determination unit 21G. Specifically, the position calculation unit 21F calculates the position of the portable device 30 based on the position information signal received by the in-vehicle receiver 22B. The position determination unit 21G determines whether the portable device 30 is inside or outside the vehicle based on the calculated position.

[0063] As described above, the method of calculating the position of the portable device 30 is not particularly limited as long as it is possible to determine whether the portable device 30 is inside or outside the vehicle. For example, the calculated position of the portable device 30 may be a relative orientation and position with respect to the vehicle 100, or may be an absolute position including longitude and latitude.

[0064] When the position determination unit 21G determines that the portable device 30 is outside the vehicle while the search radio wave strength of the search signal is limited by the strength limiting unit 21B, the restriction release unit 21C releases the restriction on the search radio wave strength. When the position determination unit 21G determines that the portable device 30 is inside the vehicle, the restriction on the search radio wave strength by the strength limiting unit 21B continues.

[0065] The control flow of the smart key system 1 according to this embodiment will be described below with reference to Fig. 7. Steps S31 to S33 are the same as those in the first embodiment. Next, in step S71, the position calculation unit 21F calculates the position of the portable device 30, and the position determination unit 21G determines whether the portable device 30 is outside the vehicle.

[0066] If the position determination unit 21G determines that the portable device 30 is not outside the vehicle (NO), the portable device 30 is inside the vehicle. In this case, one of the requirements for limiting the search radio wave intensity of the search signal is satisfied, so the process proceeds to step S51. On the other hand, if the position determination unit 21G determines that the portable device 30 is outside the vehicle (YES), the portable device 30 is outside the vehicle, so the restriction removal unit 21C removes the restriction on the search radio wave intensity in step S35. The other steps are the same as those in the second embodiment.

[0067] According to this embodiment, when the portable device 30 is outside the vehicle, the restriction on the search radio wave intensity of the search signal is lifted, so that the in-vehicle device 20 can receive the search signal at the portable receiver 32B of the portable device 30 and can receive the location information signal from the portable transmitter 32A. This makes it possible to obtain location information of the portable device 30 that is outside the vehicle.

[0068] For example, in the first to third embodiments, in accordance with the restriction on the search radio wave strength of the search signal from the vehicle-mounted transmitter 22A, a restriction may be implemented to lower or set to zero the radio wave strength of the above-mentioned location information signal transmitted from the portable transmitter 32A of the portable communication device 32.

[0069] In this case, the static electricity charged in the vehicle can be suppressed by limiting the radio wave strength of the position information signal. Note that the limitation of the radio wave strength of the position information signal does not cause any particular problem in the operation of the operation switch 33 for the portable communication device 32.

[0070] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made without departing from the spirit of the present invention described in the claims. [Explanation of symbols]

[0071] 1: smart key system, 20: vehicle-mounted device, 21: communication control device, 22: vehicle-mounted communication device, 22A: vehicle-mounted transmitter, 23: operation switch, 30: portable device, 32: portable communication device, 33: operation switch, 50: static eliminator, 100: vehicle, 101: trunk, 102: door, 105: sliding mechanism

Claims

1. A vehicle having a smart key system including an on-board device and a portable device capable of wireless communication with the on-board device, The vehicle includes a driving control device that controls driving of the vehicle, the on-vehicle device includes an on-vehicle communication unit having an on-vehicle transmitter that transmits a search signal for searching the portable device at a predetermined search radio wave intensity, and a communication control device that controls communication of the on-vehicle communication unit; each of the in-vehicle device and the portable device is provided with an operation switch for starting or stopping a main power supply of the driving control device; the communication control device controls the vehicle-mounted transmitter so as to execute a restriction to reduce or set to zero the intensity of the search radio wave transmitted from the vehicle-mounted transmitter during a period from when the main power source is started by the operation switch until when the main power source is stopped, the vehicle-mounted device is provided with a detection device for detecting an open / closed state of a trunk and a door of the vehicle; the communication control device controls the in-vehicle transmitter to release the restriction on the reduction or zeroing of the search radio wave intensity while the detection device detects that the trunk or the door is open from when the main power source is started by the operation switch until when the main power source is stopped; the portable device has a portable communication unit that receives the search signal from the vehicle-mounted transmitter and transmits a location information signal of the portable device to the vehicle-mounted device, a communication control device that, during the period from when the main power supply is started by the operation switch to when the main power supply is stopped, determines whether the portable unit is inside or outside the vehicle based on the location information signal, and controls the in-vehicle transmitter to lift the restriction on reducing or setting to zero the search radio wave strength if the portable unit is outside the vehicle.

2. 2. The vehicle having a smart key system according to claim 1, further comprising a static eliminator disposed on a surface of the vehicle for eliminating static electricity charged to the vehicle.

3. 3. The vehicle having the smart key system according to claim 1, further comprising a sliding mechanism that slides via a lubricant, and conductive particles that neutralize the static electricity stored in the sliding mechanism are added to the lubricant.

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