Wireless communication system for electric vehicle

Abstract

To provide a wireless communication system for an electric vehicle which activates an on-vehicle converter to supply electric power to locking means thereby reducing electric power consumption for a standby mode only when it is determined that an authentication code is a legitimate authentication code.SOLUTION: A wireless communication system for an electric vehicle includes: an on-vehicle unit 1 which is mounted on an electric vehicle V and can wirelessly transmit an access signal by operating an access switch 8; a portable machine 2 which may wirelessly transmit a predetermined response signal including an authentication code to the on-vehicle unit 1; determination means 4 which determines whether or not the authentication code is a legitimate authentication code; and locking control means 5 which supplies electric power to locking means 9 for restricting traveling of the vehicle to unlock it when it is determined that the authentication code is the legitimate authentication code. Provided that it is determined that the determination means 4 determines that the authentication code is the legitimate authentication code, the system activates an on-vehicle converter C to convert a voltage of a battery into a low voltage to supply electric power to the locking means 9.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system for an electric vehicle that enables the vehicle to travel in response to a response signal wirelessly transmitted from a portable device to an on-board unit. [Background technology]

[0002] A wireless communication system has become widespread, which includes a portable device carried by a passenger and capable of transmitting a vehicle-specific authentication code via radio waves, and an on-board unit capable of receiving the transmitted authentication code, and which, if the authentication code wirelessly transmitted from the portable device is a legitimate authentication code, can unlock various locks on the vehicle and permit the start of the drive source. Such a wireless communication system is configured so that, when an access button arranged on the on-board unit is pressed, an access signal is wirelessly transmitted, and the portable device that receives the access signal wirelessly transmits an authentication code, and, when the authentication code is received by the on-board unit, it can determine whether the authentication code is a legitimate authentication code. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-220088 Summary of the Invention [Problem to be solved by the invention]

[0004] When such a wireless communication system is applied to an electric vehicle (EV), the following problems arise. Electric vehicles are equipped with an onboard battery that supplies power to a drive motor to enable the vehicle to run, and since the onboard battery needs to supply power to the drive motor while suppressing heat generation, it is set to a high voltage (e.g., 72V), especially in large vehicles. Also, various electrical components attached to the vehicle, such as turn signals, require a power supply at a voltage (low voltage) lower than that of the onboard battery, depending on their specifications. Therefore, electric vehicles are provided that are equipped with an onboard converter (DC-DC converter) that can convert the voltage of the onboard battery to a low voltage and then supply power to each electrical component.

[0005] On the other hand, in the above-mentioned conventional wireless communication system, as with electrical equipment, the voltage of the vehicle battery must be converted to a low voltage by an on-board converter, and then power must be supplied to the locking means that restricts the vehicle's movement to unlock it.However, if the on-board converter is operating during the standby time before the access button is operated, there is a problem that the power consumption for standby becomes large due to the power loss caused by the voltage conversion by the on-board converter.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a wireless communication system for an electric vehicle that can reduce power consumption for standby by activating an on-board converter to supply power to a locking means only when it is determined that an authentication code is a legitimate authentication code. [Means for solving the problem]

[0007] The invention described in claim 1 is a wireless communication system for an electric vehicle that is installed in an electric vehicle equipped with an on-board battery that supplies power to a drive motor to enable the vehicle to run, and an on-board converter that converts the voltage of the on-board battery into a low voltage suitable for electrical equipment attached to the vehicle, and that can authenticate the vehicle by wirelessly transmitting an authentication code unique to the vehicle, the system comprising: an on-board unit that is mounted in the vehicle and has an operation means that can be operated at will by a passenger, and that can wirelessly transmit an access signal by operating the operation means; a portable device that can be carried by a passenger of the vehicle, and that can wirelessly transmit a predetermined response signal including the authentication code to the on-board unit when the access signal is received; The vehicle is equipped with a determination means for determining whether the authentication code is a legitimate authentication code when a response signal is received, and a lock control means for supplying power to a lock means that restricts the vehicle's travel to unlock the vehicle when the determination means determines that the authentication code is a legitimate authentication code, and is characterized in that during a standby time before the operation means is operated, power is supplied from the on-board battery without starting the on-board converter, and on condition that the determination means determines that the authentication code is a legitimate authentication code, the on-board converter is started and the voltage of the on-board battery is converted to a low voltage to supply power to the lock means.

[0008] The invention of claim 2 is characterized in that, in the wireless communication system for an electric vehicle of claim 1, the on-board unit has a control unit having the determination means and a communication circuit that enables transmission and reception via an antenna for wireless communication, and during the standby time, power is supplied from the on-board battery only to the control unit and the communication circuit.

[0009] The invention of claim 3 is characterized in that, in the wireless communication system for an electric vehicle of claim 1, when the on-board converter is operated on the condition that the determination means determines that the authentication code is a legitimate authentication code, in addition to the locking means, power converted into a low voltage is supplied to a communication system capable of transmitting and receiving control signals to electrical equipment equipped in the vehicle.

[0010] The invention of claim 4 is characterized in that, in the wireless communication system for an electric vehicle of claim 1, the on-board unit is provided with a light-emitting means, and the light-emitting means is turned on or flashes during a waiting time after transmitting the access signal until receiving the response signal. [Effects of the Invention]

[0011] According to the invention of claim 1, on the condition that the determination means determines that the authentication code is a legitimate authentication code, the in-vehicle converter is activated, the voltage of the in-vehicle battery is converted to a low voltage, and power is supplied to the locking means.Therefore, by activating the in-vehicle converter and supplying power to the locking means only when it is determined that the authentication code is a legitimate authentication code, it is possible to reduce power consumption for standby.

[0012] According to the invention of claim 2, the vehicle-mounted unit has a control unit with a determination means and a communication circuit that enables transmission and reception via an antenna for wireless communication, and during standby time, power is supplied from the vehicle battery only to the control unit and the communication circuit, thereby effectively reducing power consumption during standby time.

[0013] According to the invention of claim 3, when the in-vehicle converter is operated on the condition that the determination means determines that the authentication code is a legitimate authentication code, power converted to low voltage is supplied to the locking means as well as to a communication system capable of sending and receiving control signals to electrical equipment equipped in the vehicle, so that the in-vehicle converter can be operated when power is supplied to the locking means and the communication system, which consume relatively much power.

[0014] According to the invention of claim 4, the vehicle-mounted unit is provided with a light-emitting means, and the light-emitting means is turned on or flashes during the waiting time between transmitting the access signal and receiving the response signal, so that the passengers can be made aware that they are in a waiting time by the light-emitting means being turned on or flashing. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram showing a wireless communication system for an electric vehicle according to an embodiment of the present invention; [Figure 2] A flowchart showing control during authentication of the wireless communication system for an electric vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The wireless communication system for an electric vehicle according to this embodiment is applied to an electric vehicle (EV) consisting of a two-wheeled vehicle that is driven by supplying power to a drive motor, and is capable of authenticating the vehicle by wirelessly transmitting an authentication code unique to the vehicle.

[0017] As shown in FIG. 1, the electric vehicle V applied to this embodiment includes an on-board battery B that supplies power to a drive motor M to enable the vehicle to run, an on-board converter C that converts the voltage of the on-board battery B to a low voltage suitable for electrical equipment attached to the vehicle, and a communication system F (e.g., a Controller Area Network: CAN system) that can send and receive control signals to various electrical equipment such as turn signals.

[0018] The on-board battery B is a storage battery set to a high output voltage (e.g., 72V) particularly in large vehicles in order to supply power to the drive motor M while suppressing heat generation, etc., and can use storage batteries such as lithium-ion batteries, nickel-metal hydride batteries, lead-acid batteries (secondary batteries that can be repeatedly charged and discharged) attached to the vehicle body.

[0019] The on-board converter C is a DC-DC converter that converts DC (direct current) to DC (direct current), and in this embodiment, it is a step-down converter that converts the voltage (high voltage) of the on-board battery B to a lower voltage (low voltage). That is, high voltage power is supplied from the on-board battery B to the drive motor M, and the on-board converter C converts this voltage to a low voltage that can be supplied to various electrical components of the vehicle.

[0020] Here, the wireless communication system for an electric vehicle according to this embodiment is attached to the electric vehicle V and is capable of authenticating the vehicle by wirelessly communicating a vehicle-specific authentication code, and as shown in FIG. 1, is configured to include an in-vehicle unit 1, a portable device 2, a control unit 3 having a determination means 4 and a lock control means 5 formed therein, a communication circuit 6 connected to an antenna 7, an access switch 8 (operation means), and a lock means 9.

[0021] The in-vehicle unit 1 and the portable device 2 constitute a so-called passive keyless entry device that can authenticate each other through wireless communication to enable the vehicle to be driven. Of these, the in-vehicle unit 1 is mounted on the electric vehicle V and has an access switch 8 (operation means) that can be operated at will by the passenger, and can wirelessly transmit an access signal to the portable device 2 by radio waves by operating the access switch 8.

[0022] The portable device 2 is portable by a vehicle occupant (user), and when it receives an access signal from the in-vehicle unit 1 via an internal antenna, it can wirelessly transmit a predetermined response signal including an authentication code to the in-vehicle unit 1 via radio waves. The portable device 2 is equipped with a power source such as a battery and an antenna, and is capable of transmitting and receiving response signals and the like to and from the antenna 7 of the in-vehicle unit 1.

[0023] The control unit 3 is made up of, for example, a microcomputer mounted in the in-vehicle unit 1, and is for controlling wireless communication and authentication between the in-vehicle unit 1 and the portable device 2, and is configured with a determination means 4 and a lock control means 5. When the determination means 4 determines that the authentication code is a legitimate authentication code, the lock control means 5 supplies power to a lock motor 9a of the lock means 9 that restricts the vehicle from traveling, thereby releasing the lock.

[0024] The locking means 9 according to this embodiment includes a locking bar that can move between a locked position, which locks the vehicle's handlebars, and an unlocked position, which unlocks the handlebars, and a locking motor 9a that is made up of a motor or the like that moves the locking bar between the locked and unlocked positions. When the determination means 4 determines that the authentication code is a legitimate authentication code, the locking motor 9a is powered to drive it, thereby moving the locking bar to the unlocked position and unlocking the handlebars. This releases the restriction on vehicle travel imposed by the locking means 9.

[0025] The control unit 3 is also connected to a communication circuit 6 and an LED 10 (light-emitting means). The communication circuit 6 is connected to an antenna 7 and is capable of controlling wireless communication between the antenna 7 and the portable device 2. The LED 10 is disposed in a visible position on the in-vehicle unit 1, and is configured to light up or blink during the waiting time until a response signal is received from the portable device 2 after an access signal is transmitted via the antenna 7 by operating the access switch 8.

[0026] Furthermore, the control unit 3 is connected to a protection circuit 11 and a step-down circuit 12. The protection circuit 11 is made up of a circuit for preventing overcurrent from flowing, and is connected to the in-vehicle battery B and the step-down circuit 12. The step-down circuit 12 is made up of a circuit for stepping down the input voltage from the in-vehicle battery B, and for example, steps down the voltage V0 (e.g., 72 V) of the in-vehicle battery B to a predetermined voltage V1 (e.g., 12 V) and a voltage V2 (e.g., 5 V) (both are converted to DC voltage), so that power can be supplied to predetermined components of the wireless communication system for an electric vehicle.

[0027] Here, the control unit 3 according to this embodiment is connected to the start-up circuit 13. The start-up circuit 13 starts the in-vehicle converter C, converts the voltage of the in-vehicle battery B to a low voltage, and supplies power to the locking means 9, on condition that the determination means 4 has determined that the authentication code is a legitimate authentication code. As a result, during the standby time before the access switch 8 (operation means) is operated, power is supplied from the in-vehicle battery B without starting the in-vehicle converter C, and, on condition that the determination means 4 has determined that the authentication code is a legitimate authentication code, the start-up circuit 13 starts the in-vehicle converter C, converts the voltage of the in-vehicle battery B to a low voltage, and supplies power to the locking motor 9a of the locking means 9.

[0028] Furthermore, the wireless communication system for an electric vehicle according to this embodiment is configured so that during standby time, the on-board converter C is not operated, and power is supplied from the on-board battery B only to the control unit 3 and the communication circuit 6. Furthermore, when the on-board converter C is operated, on the condition that the determination means 4 determines that the authentication code is a legitimate authentication code, the wireless communication system for an electric vehicle according to this embodiment is configured so that power converted into low voltage is supplied to the lock means 9 as well as to the communication system F (CAN system) that can send and receive control signals to electrical components equipped in the vehicle.

[0029] Next, the control of the wireless communication system for an electric vehicle according to this embodiment will be described with reference to the flowchart of FIG. First, in S1, it is determined whether or not the access switch 8 has been operated, and if it is determined that the access switch 8 has been operated, the process proceeds to S2, where an access signal is transmitted from the antenna 7 to the portable device 2, and a response signal including an authentication code is received from the portable device 2 at the antenna 7, and authentication is performed by the determination means 4. Note that the period until it is determined in S1 that the access switch 8 has been operated is a standby period.

[0030] Then, when authentication is performed in S2, the LED 10 is turned on (or blinked) in S3, and then the process proceeds to S4, where the determination means 4 determines whether or not a valid authentication code has been received from the portable device 2 as a result of the authentication. If it is determined in S4 that a valid authentication code has been received from the portable device 2, the start-up circuit 13 transmits a start-up signal to the vehicle-mounted converter C, and the vehicle-mounted converter C is activated in S5.

[0031] Thereafter, in S6, power is supplied from the on-board battery B to the locking means 9 via the on-board converter C to drive the lock motor 9a. As a result, on condition that the determination means 4 determines that the authentication code is a legitimate authentication code, the on-board converter C is started, and the voltage of the on-board battery B is converted to a low voltage and can be supplied to the locking motor 9a of the locking means 9.

[0032] Further, the process proceeds to S7, where power is supplied from the vehicle battery B to the locking means 9 via the vehicle converter C, activating the communication system F. As a result, on the condition that the determination means 4 determines that the authentication code is a legitimate authentication code, the vehicle converter C is activated, thereby making it possible to supply power converted into low voltage to the communication system F (CAN system) in addition to the locking means 9.

[0033] On the other hand, if it is not determined in S4 that a valid authentication code has been received from the portable device 2, it is determined in S8 whether a predetermined time has elapsed, and S3 and S4 are repeated until the predetermined time has elapsed, so that the LED 10 continues to light up and authentication by the determination means 4 continues, and once the predetermined time has elapsed, the series of controls ends.

[0034] According to the wireless communication system for an electric vehicle of this embodiment, on the condition that the determination means 4 determines that the authentication code is a legitimate authentication code, the in-vehicle converter C is activated, the voltage of the in-vehicle battery B is converted to a low voltage, and power is supplied to the locking means 9. Therefore, by activating the in-vehicle converter C and supplying power to the locking means 9 only when it is determined that the authentication code is a legitimate authentication code, it is possible to reduce power consumption for standby.

[0035] Furthermore, the in-vehicle unit 1 according to this embodiment includes a control unit 3 having a determination means 4 and a communication circuit 6 that enables transmission and reception by an antenna 7 for wireless communication, and during standby time, power is supplied from the in-vehicle battery B only to the control unit 3 and the communication circuit 6, thereby effectively reducing power consumption during standby time. Note that, according to this embodiment, power can be supplied only to the control unit 3 and the communication circuit 6 at a voltage stepped down by the step-down circuit 12.

[0036] Furthermore, according to the wireless communication system for an electric vehicle of this embodiment, when the in-vehicle converter C is activated, on the condition that the determination means 4 determines that the authentication code is a legitimate authentication code, power converted into a low voltage is supplied to the locking means 9 as well as to the communication system F, which is capable of transmitting and receiving control signals to electrical components equipped in the vehicle. Therefore, the in-vehicle converter C can be activated when power is supplied to the locking means 9 and the communication system F, which consume a relatively large amount of power.

[0037] Furthermore, the vehicle-mounted unit 1 of this embodiment is equipped with an LED 10 as a light-emitting means, and the LED 10 is lit or flashes during the waiting time after transmitting an access signal until a response signal is received, so that the occupants can be made aware that the waiting time is approaching by the LED 10 being lit or flashing.

[0038] Although the present embodiment has been described above, the present invention is not limited to this. For example, the lock motor 9a serving as the drive means for the lock means 9 may be replaced with another actuator. Furthermore, the lock means 9 is not limited to locking the steering as in this embodiment, but may be another type of lock means that restricts the vehicle from traveling. Furthermore, the LED 10 may be replaced with another light-emitting means that can emit light. Note that while this embodiment is applied to an electric motorcycle, it may also be applied to other electric vehicles (such as automobiles, trucks, or industrial vehicles such as construction machinery and agricultural machinery). [Industrial Applicability]

[0039] The present invention can also be applied to devices with different external shapes or devices with additional functions, provided that they have the same gist as the present invention. [Explanation of symbols]

[0040] 1 In-vehicle unit 2. Portable devices 3. Control Unit 4 Judgment means 5 Lock control means 6. Communication Circuits 7 Antenna 8 Access switch (operating means) 9 Locking means 9a Lock motor 10 LED (light emitting means) 11 Protection circuit 12 Step-down circuit 13 Starter circuit V Electric Vehicle M Drive motor B. Vehicle battery C. In-vehicle converter F Communication system (CAN system)

Claims

1. A wireless communication system for an electric vehicle is provided in an electric vehicle including an on-board battery that supplies power to a drive motor to enable the vehicle to run, and an on-board converter that converts the voltage of the on-board battery to a low voltage suitable for electrical equipment attached to the vehicle, and is capable of authenticating the vehicle by wirelessly communicating an authentication code unique to the vehicle, an in-vehicle unit that is mounted in the vehicle and has an operation means that can be operated arbitrarily by a passenger, and that can wirelessly transmit an access signal by operating the operation means; a portable device that can be carried by a vehicle occupant and that can wirelessly transmit a predetermined response signal including the authentication code to the in-vehicle unit when the in-vehicle unit receives the access signal; a determination means for determining whether the authentication code is a legitimate authentication code when the response signal is received; a lock control means for supplying power to a lock means that restricts the vehicle from traveling and unlocking the lock when the determination means determines that the authentication code is a legitimate authentication code; Equipped with a power supply means for supplying power from the on-board battery without starting the on-board converter during a standby time before the operation means is operated, and starting the on-board converter and converting the voltage of the on-board battery to a low voltage to supply power to the locking means on condition that the determination means determines that the authentication code is a legitimate authentication code.

2. 2. The wireless communication system for an electric vehicle according to claim 1, wherein the on-board unit includes a control unit having the determination means and a communication circuit that enables transmission and reception via an antenna for wireless communication, and during the standby time, power is supplied from the on-board battery only to the control unit and the communication circuit.

3. 2. The wireless communication system for an electric vehicle according to claim 1, wherein, when the on-board converter is operated on the condition that the determination means determines that the authentication code is a legitimate authentication code, in addition to the locking means, power converted into a low voltage is supplied to a communication system capable of transmitting and receiving control signals to electrical components equipped in the vehicle.

4. 2. The wireless communication system for an electric vehicle according to claim 1, wherein the on-board unit includes a light emitting means, and the light emitting means is turned on or blinks during a waiting time from when the access signal is transmitted until when the response signal is received.

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