JP2002280950A - Stationary side communication system and stationary side communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stationary side communication system, that can ensure security in the case of conducting near distance wireless communication with a mobile wireless phone and suppress unwanted power consumption to the utmost. SOLUTION: The transmission power and the reception sensitivity of a Bluetooth communication section 27 of the stationary side communication system 12 are adjusted, so that communication is executed only for a Bluetooth communication section 24 of a mobile phone 3 placed on a placing base 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed-side communication device comprising short-range wireless communication means, and a fixed-side communication device similarly provided with short-range wireless communication means and arranged in a vehicle. About.

[0002]

2. Description of the Related Art For example, as shown in FIG. 6, a navigation device 2 mounted on a vehicle 1 communicates via a portable telephone 3 to communicate via a base station 4 and the Internet (including a telephone network) 5. In order to obtain necessary information from a Web server or the like (not shown), the following system has been devised.

[0003] That is, a Bluetooth communication unit (module) 6 is arranged in the cabin of the vehicle 1 and a modem (not shown) is provided.
Is configured to be able to communicate with the navigation device 2 via the. On the other hand, a similar Blue
The tooth communication unit 7 is arranged. When the user carrying the mobile phone 3 is located in the vehicle cabin, a communication link (piconet) is established between the Bluetooth communication units 6 and 7, and the navigation device 2 is connected via the Bluetooth communication units 6 and 7. To communicate with the mobile phone 3 to access the Internet 5 via the mobile phone 3.

[0004]

By the way, in the system as shown in FIG. 6, the communication link between the Bluetooth communication units 6 and 7 is automatically established at the same time when the user carrying the portable telephone 3 is located in the vehicle interior. In order for the user to obtain a good feeling of use, the Bluetooth 1
h It is necessary to always supply power to the communication unit 6. Bl
In uetooth, there is a case where the mode shifts to a low power consumption mode in order to suppress power consumption before a communication link is established. However, for the vehicle 1 that operates on a battery, it is desirable to minimize unnecessary power consumption.

Further, if the Bluetooth communication unit 6 is always powered on, communication with an unspecified Bluetooth communication unit which is not originally supposed to perform communication may occur. Although the above security is considered, it cannot be said that there is no possibility that data held by the vehicle 1 will leak. In addition, when unnecessary communication is performed, power is wasted.

The present invention has been made in view of the above circumstances, and has as its object to secure security and minimize unnecessary power consumption when performing short-range wireless communication with a portable wireless telephone. And a fixed-side communication device capable of minimizing unnecessary power consumption in order to perform short-range wireless communication with communication means possessed by a vehicle occupant. It is in.

[0007]

According to the first aspect of the present invention, the transmission power and the reception sensitivity of the short-range wireless communication means are set to the values of the portable wireless telephone set on the mounting table. It is adjusted so that communication is possible only with short-range wireless communication means. That is, when the user places the portable wireless telephone on the mounting table, short-range wireless communication is performed with the communication device side, so that the fixed-side communication device limits the communication target to the portable wireless telephone. be able to.

Therefore, it is possible to prevent an attempt to communicate with an unspecified portable radio telephone provided with a short-range wireless communication means, and to reduce the transmission power and the reception sensitivity in the short-range wireless communication means on the communication device side. Can be set to a minimum according to the communication area, and power consumption can be suppressed.

According to the fixed-side communication device of the second aspect,
The control means, while the state where the portable wireless telephone is mounted on the mounting table is detected by the telephone detection means,
Turn on the power to the short-range wireless communication means on the device side. Therefore, the short-range wireless communication means on the communication device side is turned on only when the communication target is surely present in the communication area, so that the power consumption can be further suppressed.

According to the third aspect of the present invention, the control means turns on the power to the short-range wireless communication means when the presence of the occupant in the vehicle compartment is detected by the occupant detection means. Control. That is, when an occupant is present in the passenger compartment and the occupant carries a mobile communication device having a short-range wireless communication unit, short-range wireless communication with the fixed communication device is performed. The probability is extremely high.

Therefore, in such a case, the power consumption of the vehicle can be suppressed by turning on the power to the short-range wireless communication means of the fixed-side communication device and operating it. Also,
It is possible to limit the communication target in the short-range wireless communication means of the fixed-side communication device to the short-range wireless communication means provided in the mobile communication device carried by the occupant.

According to the fourth aspect of the present invention, the control means cuts off the power supplied to the short-range wireless communication means when the presence of the occupant is not detected by the occupant detection means. Therefore, when the occupant gets off and the communication target in the short-range wireless communication unit of the fixed-side communication device no longer exists, unnecessary power consumption can be suppressed.

According to the fifth aspect of the present invention, since the occupant detection means is an ignition key switch disposed in the vehicle, equipment previously disposed in the vehicle can be used. In addition, the ignition key switch is turned on and off by the occupant performing a key operation, so that the presence of the occupant can be reliably detected.

[0014]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIG. The same parts as those in FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 1 showing a functional block diagram of the electrical configuration, a fixed communication device 12 is arranged in the vehicle 1 instead of the Bluetooth communication unit 6.

The portable telephone (portable wireless telephone) 3 includes a microphone 13 for transmitting and a speaker 14 for receiving, and audio signals input and output through these microphones are used for audio processing including an audio codec and the like. The processing is performed in the unit 15.

The telephone communication section 16 converts the transmission signal output from the audio processing section 15 into, for example, π / 4 shift DQPSK (Dif
When the signal is converted to a ferential quadrature (phase shift keying) signal and subjected to quadrature modulation, an 800 MHz band radio signal is transmitted from the antenna 17 to the base station 4. In addition, the telephone communication unit 16 demodulates a signal transmitted from the base station 4 and received by the antenna 17 and outputs the demodulated signal to the audio processing unit 15.

The CPU 18 operates based on a control program stored in the ROM of the memory 19 and controls the voice processing unit 15 and the telephone communication unit 16. The CPU 18 receives an operation signal when the user operates the keypad 20, performs processing according to the operation signal, and outputs a display control signal to a display 21 such as an LCD to display a screen. Is controlled.

The power supply circuit section 22 includes a battery (secondary battery)
The DC power supply from the power supply 23 is stabilized to supply the operation power supply Vcc to each electrical component of the mobile phone 3. In addition, the mobile phone 3 includes a Bluetooth communication unit (short-range wireless communication unit) 24, and the CPU 18 uses the Bluetooth communication unit 24 to perform short-range wireless communication (for example, communication distance 1).
(About 0 m).

On the other hand, the fixed-side communication device 12 is, for example, A, so that the mobile phone 3 can be placed in a substantially vertically stable state, for example, like a charger for a battery 23.
A mounting table 25 made of BS resin or the like is provided. Inside the mounting table 25, a CPU (microcomputer) 26, a Bluetooth communication unit (short-range wireless communication means) 27, a modem unit 28, and the like are arranged.

The CPU 26 performs short-range wireless communication with the mobile phone 3 mounted on the mounting table 25 using the Bluetooth communication unit 27. Modem section 28
Is used for the CPU 26 to communicate with the navigation device (external device) 2.

The fixed communication device 12 is externally supplied with a control power supply Vcc generated from a battery power supply (not shown) of the vehicle 1.
A power supply circuit for generating cc may be arranged inside the fixed communication device 12. The fixed communication device 12 configured as described above is installed in a vehicle interior, for example, between a driver's seat and a passenger seat.

The Bluetooth communication unit 27 has basically the same configuration as the Bluetooth communication unit 24 on the mobile phone 3 side, and includes a communication control unit 29, a transmission amplifier 30, an attenuator (ATT) 31, a reception unit It comprises an amplifier 32 and a communication antenna 33. The communication control unit 29 is C
A control circuit similar to the PU 26 and the like, which transfers data with the CPU 26 and controls short-range wireless communication with the Bluetooth communication unit 24 of the mobile phone 3 via the communication antenna 33. It has become. Near field communication is based on the Bluetooth protocol,
This is performed using a radio signal in the 2.4 GHz band.

In the Bluetooth communication unit 27, the transmission power of the radio signal set by the amplification factor of the transmission amplifier 30, the attenuation factor of the attenuator 31, the directional characteristics of the communication antenna 33, the antenna gain, etc. The reception sensitivity set by the amplification factor of the antenna 33 and the reception amplifier 32 is such that communication is possible only when the Bluetooth communication unit 24 is in a very close proximity state by mounting the mobile phone 3 on the mounting table 25. (For example, several tens cm or less in communication distance).

Next, the operation of this embodiment will be described.
In a state where no one is in the vehicle 1, for example,
Assuming that the Bluetooth communication unit 27 of the fixed communication device 12 is a master, the Bluetooth communication unit 27 blows an IQ packet for “inquiry” toward the mounting table 25 as a communication area with the set weak transmission power. I'm casting.

Then, the driver carrying the mobile phone 3 gets on the vehicle 1 and mounts the mobile phone 3 on the fixed communication device 1.
When the mobile phone 3 is mounted on the mounting table 25, the Bluetooth
h The communication unit 24 (slave) can receive the IQ packet broadcast by the communication unit 27 via the antenna 24a, and the communication unit 24 transmits an FHS for transmitting the attribute as a slave in response to the reception of the IQ packet. The packet is transmitted to the communication unit 27 ("inquiry").

The communication unit 27 that has received the FHS packet
The ID packet is transmitted to the communication unit 24, and the communication unit 24 returns the same ID packet as a reception confirmation of the ID packet. Then, the communication unit 27 has its own Blueto
An FHS packet for transmitting the oth address and the Bluetooth clock is transmitted to the communication unit 24 (“call”). The communication unit 24 that has received the FHS packet returns an ID packet as a reception confirmation. Thus, the synchronization establishment phase is completed, and the communication units 27 and 24 are in a state where communication is possible.

Then, the communication units 27 and 24 shift to the next communication connection phase, and perform communication between them as necessary. For example, when the driver operates the navigation device 2 while driving the vehicle 1 to obtain necessary information from the Web server via the Internet 5, the navigation device 2 transmits the information to the fixed communication device 12. On the other hand, a connection request to the Web server is output.

Then, the CPU 26 of the fixed-side communication device 12
Is the mobile phone 3 via the Bluetooth communication units 27 and 24.
Sends the connection request to the
Communicates with the base station 4 through the telephone communication unit 16 and downloads necessary information (content) from the Web server via the Internet 5. Then, the downloaded information is transmitted from the fixed communication device 12 to the navigation device 2 via the reverse route.

In this way, after necessary communication is performed between the fixed communication device 12 and the portable telephone 3 using Bluetooth as an interface during driving of the vehicle 1 or the like, the driver ends driving and the vehicle 1 Mobile phone 3
When the device is taken out of the mounting table 25, communication between the communication units 27 and 24 is disabled, and a Bluetooth communication link (piconet) is used.
Is disconnected.

As described above, according to the present embodiment, the transmission power and the reception sensitivity of the Bluetooth communication unit 27 of the fixed-side communication device 12 are determined by the Bluetooth communication unit of the mobile phone 3 mounted on the mounting table 25. Since the adjustment is made so that communication is possible only with the mobile phone 24, the fixed-side communication device 12 can limit the communication target of the short-range wireless communication to the mobile phone 3.

Therefore, it is possible to prevent an attempt to communicate with an unspecified portable telephone having a similar Bluetooth communication unit, and to set the transmission power and the reception sensitivity in the Bluetooth communication unit 27 of the communication device 12 to the above-mentioned communication. It can be set to a minimum according to the area, and power consumption can be suppressed.

(Second Embodiment) FIGS. 2 and 3 show a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. Only different parts will be described. Fixed-side communication device 34 of the second embodiment
Has a push switch 35 disposed inside the mounting table 25. The operator 35a of the push switch (telephone detecting means) 35 projects outside through an opening 36 provided on the surface of the mounting table 25, and is configured to be vertically movable. At the same time, it is urged upward by the urging force of a spring (not shown).

The push switch 35 is a normally open type, and when the mobile phone 3 is mounted on the mounting table 25, the mobile phone 3
Due to the weight, the operator 35a is pushed downward, and the fixed contact 35b and the movable contact 35c are connected. The fixed contact 35b is connected to the ground, and the movable contact 35c is pulled up to the power supply Vcc via the resistor 37. The movable contact 35c is connected to the CPU
A low-level telephone detection signal SON is output to a CPU (control means) 38 instead of the CPU 26.

The power supply Vcc is connected to the Bluetooth communication unit 27 of the fixed communication device 34 via a normally open switch 39.
Are supplied, and the opening and closing control of the switch 39 is performed by the CPU 38. Other configurations are the same as in the first embodiment. Note that the configurations shown in these functional block diagrams do not necessarily reflect the physical positional relationship in an actual component, but basically disclose an electrical configuration.

Next, the operation of the second embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing the control contents of the processing executed by the CPU 38. When the mobile phone 3 is not mounted on the mounting table 25 of the fixed-side communication device 34, the push switch 35 is open (the operation element 35a is in a state shown by a broken line in FIG. 2).
The input port of signal SON of 38 is high level and signal SON
ON is inactive.

The CPU 38 waits until the signal SON becomes active (low level) (step A1). Therefore, in this standby state, the power supply Vcc is not supplied to the Bluetooth communication unit 27, and the transmission of the radio signal (IQ packet) is not performed.

In this state, as in the first embodiment, when the driver carrying the mobile phone 3 gets into the vehicle 1 and places the mobile phone 3 on the mounting table 25, the operator 35a of the push switch 35 Is pushed downward by the weight of the mobile phone 3 (the state shown by the solid line in FIG. 2),
5b and the movable contact 35c are connected.

Then, the input port of the signal SON of the CPU 38 becomes the ground level (low level) and the signal SON becomes active (step A1, "YES").
PU 38 closes switch 39 and sets Bluetooth communication unit 2
The power supply Vcc is supplied (ON) to the power supply 7 (step A2).
In the state of the solid line shown in FIG. 2, for convenience of illustration, a gap is provided between the mobile phone 3 and the mounting table 25, but actually, both are in close contact with each other, and the upper end of the operator 35 a is Mounting table 2
5 is flush with the upper surface.

The Bluetooth communication unit 27 starts up when the power supply Vcc is supplied, and starts transmitting IQ packets. As in the first embodiment, the Bluetooth communication unit 2 of the mobile phone 3
4, short-range wireless communication is started, and a communication link is established. Then, the CPU 38 performs necessary communication processing with the mobile phone 3 via the communication units 27 and 24 in response to a request from the navigation device 2 (step A).
3). Thereafter, as long as the signal SON does not become inactive in step A4 ("NO"), the CPU 38 returns to step A3 to execute communication processing.

When the driver finishes driving and goes out of the cabin of the vehicle 1 and takes the mobile phone 3 out of the mounting table 25, the communication between the communication units 27 and 24 is disabled, and the Bluetooth communication is disabled.
The oth communication link (piconet) is disconnected. Also,
At this time, the operating element 35a of the push switch 35 is pushed upward by the urging force of the spring, so that the fixed contact 35b and the movable contact 35c are separated. Then, the signal SON becomes inactive (step A4, "Y
ES "), the CPU 38 opens the switch 39 and
Stop supply of power Vcc to the oth communication unit 27 (OF
F) (Step A5). Then, the process returns to step A1, and waits until the signal SON changes to active again.

As described above, according to the second embodiment, the CPU
The power supply Vcc is supplied to the Bluetooth communication unit 27 of the communication device 34 while the state in which the mobile phone 3 is mounted on the mounting table 25 is detected by the push switch 35.
Therefore, the power supply VCC is supplied to the Bluetooth communication unit 27 only when the communication target surely exists in the communication area. Therefore, power consumption can be further suppressed.

(Third Embodiment) FIGS. 4 and 5 show a third embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals, and their description will be omitted. Only the parts will be described. Fixed-side communication device 1 in the first embodiment
2 is replaced by a fixed-side communication device 40. The fixed communication device 40 includes a CPU (microcomputer, control means) 41, a Bluetooth communication unit (short-range wireless communication means) 4
2, a modem section 43, a power supply circuit section 44, and the like.

The power supply circuit section 44 stabilizes the DC power supply from the battery 45 of the vehicle 1 and supplies the operating power supply Vcc. And Blueto
The supply of the operation power supply Vcc to the oth communication unit 42 is performed through a normally open switch 46.
The opening and closing control of the switch 46 is performed by the CPU 41.

The CPU 41, like the CPU 26 in the fixed-side communication device 12 of the first embodiment,
Short-range wireless communication is performed using the communication unit 42. The modem unit 43, like the modem unit 28,
U41 is used to communicate with the navigation device 2.

An ignition key switch (hereinafter referred to as IG)
An occupant detection means (hereinafter referred to as a switch) 47 is disposed on the vehicle 1 side. ) To “IGNITION O
N ", the detection signal IGON is sent to the CPU 41.
Output. This fixed side communication device 40
Is installed in the vehicle 1, for example, inside a dashboard. Other configurations are the same as in the first embodiment.

Next, the operation of the third embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the control contents of the processing executed by the CPU 41. When no driver is in the vehicle 1, the IG switch 4
7 is OFF (the detection signal IGON is inactive). Then, the CPU 41 determines that the IG switch 47 is
It waits until it becomes N (step B1). Therefore,
In this standby state, the power supply Vcc is not supplied to the Bluetooth communication unit 42, and no radio signal is transmitted.

In this state, when the driver carrying the portable telephone 3 gets on the vehicle 1 and turns on the IG switch 47 to start the engine, the signal IGON becomes active (step B1, "YES"). The CPU 41
The switch 46 is closed and the power supply Vcc is supplied to the Bluetooth communication unit 42.
Is supplied (ON) (step B2).

The Bluetooth communication unit 42 is activated by the supply of the power Vcc and starts transmitting the IQ packet, and communicates with the Bluetooth communication unit 24 of the mobile phone 3 as in the first and second embodiments. Starts short-range wireless communication, and a communication link is established. Then, the CPU 41 performs necessary communication processing with the mobile phone 3 via the communication units 42 and 24 in response to a request from the navigation device 2 (step B3). Thereafter, as long as the IG switch 47 is not turned off in step B4 (“N
O ") Return to step B3 to execute communication processing.

When the driver turns off the IG switch 47 to stop the engine when the driver finishes driving and goes out of the cabin of the vehicle 1, communication between the communication units 42 and 24 is disabled, and Bluetooth communication is disabled. The link (piconet) is disconnected. At this time, the CPU 41 determines in step B
4 to determine “YES”, open switch 46 and
Stop supply of power Vcc to the oth communication unit 42 (OF
F) (Step B5). Then, the process returns to step B1, and waits until the IG switch 47 changes to ON again.

As described above, according to the third embodiment, the CPU
41 controls the Bluetooth communication unit 42 to turn on the power supply Vcc when the presence of the occupant in the vehicle compartment is detected by the IG switch 47, so that the occupant in the vehicle compartment carries the mobile phone 3 If short-range wireless communication with the fixed-side communication device 40 is performed, the power consumption of the vehicle 1 can be suppressed by turning on the power supply Vcc and operating the Bluetooth communication unit 42. it can. Further, the short-range wireless communication target of the fixed-side communication device 40 is
It is possible to limit to the mobile phone 3 carried by the occupant.

When the presence of the occupant is no longer detected by the IG switch 47, the CPU 41
Since the power supply Vcc supplied to the oth communication unit 42 is cut off, unnecessary power is consumed when the occupant gets off and the short-range wireless communication target of the fixed-side communication device 40 no longer exists. Can be suppressed.

Since the CPU 41 detects the presence of an occupant in the vehicle cabin based on the ON / OFF state of the IG switch 47 disposed in the vehicle 1, it is necessary to use facilities that are pre-arranged in the vehicle 1. Can be. Also,
The IG switch 47 is turned on and off by the key operation of the occupant, so that the presence of the occupant can be reliably detected.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications or extensions are possible. The setting of the master and the slave between the Bluetooth communication units 24 and 42 may be reversed. Instead of the modem unit 28 of the fixed communication device 12 or the modem unit 43 of the fixed communication device 40, an in-vehicle LAN (Local Area Neighbor) is used.
twork) interface, navigation device 2
It may be configured to perform communication with. The external device is not limited to the navigation device 2 and may be, for example, a hands-free communication device of a mobile phone. The fixed-side communication device 12 according to the first embodiment is not limited to the one installed in the cabin of the vehicle 1, and is configured to be connected to, for example, a personal computer (PC) used by a user at home. The present invention may be applied to a system in which a portable wireless telephone can be used via short-range wireless communication for performing personal computer communication when a user having a portable wireless telephone approaches a personal computer.

The mounting table is not limited to the one on which the portable radio telephone is mounted substantially vertically, but may be the one mounted horizontally or mounted obliquely. In the third embodiment, the power supply circuit section 44 of the fixed communication device 40 may be disposed on the vehicle 1 side, and the power supply Vcc may be supplied from the vehicle 1 side. Further, the occupant detection means is not limited to the IG switch 47, and may detect the presence of the occupant in the interior of the vehicle, such as installing an infrared sensor in the interior of the vehicle or detecting the state of attachment / detachment of the seat belt. Anything that can be detected may be used. The short-range wireless communication is not limited to the Bluetooth protocol. For example, DSRC (Dedicated Short Ran
ge Communication) may be used. In addition,
The communication distance can be adjusted to 10 m by adjusting the power for communication as appropriate.
Anything can be set as long as it can be set before and after. The portable wireless telephone may be a PHS (Personal Handyphone System).

[Brief description of the drawings]

FIG. 1 is a first embodiment in which the present invention is applied to a vehicle, and is a functional block diagram showing an electrical configuration.

FIG. 2 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 3 is a flowchart illustrating processing executed by a CPU of the fixed communication device;

FIG. 4 is a view corresponding to FIG. 1, showing a third embodiment of the present invention;

FIG. 5 is a diagram corresponding to FIG. 3;

FIG. 6 is a diagram illustrating a state in which a navigation device mounted on a vehicle performs communication via a mobile phone according to the related art.

[Explanation of symbols]

3 is a mobile phone (portable wireless telephone), 12 is a fixed-side communication device, 24 is a Bluetooth communication unit (short-range wireless communication means), 27 is a Bluetooth communication unit (short-range wireless communication means), and 38 is a CPU (control means). ) And 41 are a CPU (control means), 42 is a Bluetooth communication unit (short-range wireless communication means), and 47 is an ignition key switch (occupant detection means).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H04M 1/73 H04B 7/26 R 1/738 X 109R F-term (Reference) 5K023 AA07 AA09 BB04 BB11 KK04 LL04 LL05 MM25 MM27 NN06 PP12 5K027 AA11 AA16 BB02 BB04 BB17 CC08 EE11 GG04 HH26 KK02 KK07 MM04 5K067 AA30 AA43 BB04 EE03 EE12 EE35 GG01 HH12 KK05

Claims (5)

[Claims] 1. A mounting table on which a portable wireless telephone having a short-range wireless communication means is mounted, and a short-range wireless communication means of the portable wireless telephone mounted on the mounting table. A fixed-side communication device comprising: a short-range wireless communication unit whose transmission power and reception sensitivity are adjusted so that only communication is possible. 2. A telephone detecting means for detecting that a portable radio telephone is mounted on the mounting table, and a device side while the mounted state of the portable radio telephone is detected by the telephone detecting means. 2. The fixed-side communication device according to claim 1, further comprising control means for controlling power to be supplied to said short-range wireless communication means. 3. An occupant detection means mounted on a vehicle for detecting the presence of an occupant in a vehicle interior, a short-range wireless communication means configured to be able to communicate at least within a range of the interior of the vehicle, and the occupant. A fixed-side communication device comprising: control means for controlling the power to be supplied to the short-range wireless communication means when the presence of an occupant is detected by the detection means. 4. The power supply to the short-range wireless communication means when the presence of the occupant is no longer detected by the occupant detection means. 3. The fixed-side communication device according to 3. 5. The fixed-side communication device according to claim 3, wherein the occupant detection means is an ignition key switch disposed on a vehicle.