KR20200126305A - A smart key and method for controlling the smart key - Google Patents

Abstract

A smart key of the present invention includes: an LF receiving unit for receiving an LF signal including a command message indicating the opening or closing of a vehicle door from a vehicle; an RF transmitting unit for transmitting an RF signal for the LF signal to the vehicle; a sensor unit for sensing user′s movement; and a micro control unit for generating a control command for controlling the ON/OFF switching of the sensor unit in response to the LF signal.

Description

Smart key and control method of smart key {A SMART KEY AND METHOD FOR CONTROLLING THE SMART KEY}

The present invention relates to a smart key system in a vehicle.

In general, in a smart key system in a vehicle, a driver (or user) carries a smart key (or FOB Key), and a smart key unit (hereinafter referred to as SMK Unit) mounted on the vehicle is LF ( Functions such as locking/unlocking the vehicle door, starting and applying power, etc. only when authenticating the user by analyzing the encryption code received from the smart key using Low Frequency) and RF (Radio Frequency) communication By performing, it refers to a system that prevents and prevents vehicle theft accidents.

As described above, the smart key (or FOB Key) serves as a vehicle key, and uses a 3V lithium-ion battery, and various studies to improve battery consumption have recently been conducted.

As one of the researches to improve battery consumption, a sensor that detects the movement of the smart key (for example, a vibration sensor) is built inside the smart key, and only when the sensor detects the movement of the smart key, a specific function (vehicle A method of improving battery consumption by operating the lock/unlock of the door, starting and applying power, etc.) is being studied.

However, existing studies have limitations in improving battery consumption only in certain situations, and rather, there is a problem that battery consumption is greater when a sensor for detecting the movement of a smart key is always on (continuously).

In addition, they are exposed to hacking problems such as Relay Station Attack (RSA), and hacking defense measures are needed.

Accordingly, an object of the present invention is to maximize the battery efficiency built into the smart key by adjusting the function of the smart key to improve the above-described problems, and at the same time, a smart device capable of preventing hacking such as relay station attack (hereinafter, RSA) It is to provide a control method of keys and smart keys.

A method for controlling a smart key according to an aspect of the present invention for achieving the above object includes an LF receiving unit receiving a low frequency (LF) signal from a vehicle, and a radio frequency (RF) signal as a response to the LF signal. A method for controlling a smart key including an RF transmission unit for transmitting to a vehicle, a sensor unit for detecting a movement of a user, and a micro control unit, wherein the LF receiving unit includes a command message indicating the opening or closing of the vehicle door from the vehicle. Receiving a signal; And controlling, by the micro-control unit, on (ON) and off (OFF) of the sensor unit detecting movement of the smart key in response to the LF signal. Includes.

According to another aspect of the present invention, a smart key includes: an LF receiver configured to receive an LF signal including a command message indicating opening or closing of a vehicle door from a vehicle; An RF transmitter for transmitting an RF signal for the LF signal to the vehicle; A sensor unit for detecting a user's movement; And a micro control unit generating a control command for controlling ON and OFF switching of the sensor unit in response to the LF signal.

In a smart key with a built-in sensor (for example, a vibration sensor) that detects the movement of a conventional smart key, the sensor is always on, so battery consumption is large due to the always-on sensor. By adjusting the sensing intensity (sensing sensitivity, sensing period, and sensing frequency) to be turned off in the vehicle and outdoors in the vehicle, the battery efficiency can be improved compared to the conventional method, and the LF receiver is turned on and off. By properly controlling the (OFF) state, it is possible to additionally expect a battery saving effect due to the LF receiver as well as protection against hacking such as RSA.

1 is a block diagram of a smart key according to an embodiment of the present invention.
2 is a flow chart of messages exchanged between a smart key and a vehicle according to an embodiment of the present invention.
3 is a flow chart illustrating a method of controlling a smart key according to an embodiment of the present invention.
4 is a diagram illustrating a situation in which a smart key is located within an LF reception distance according to an embodiment of the present invention.
5 is a diagram illustrating a situation in which a smart key is located outside an LF reception distance according to an embodiment of the present invention.
6 is a diagram illustrating a situation in which a smart key is located inside a vehicle (inside a vehicle) according to an embodiment of the present invention.

As described above, when a sensor unit (for example, a vibration sensor) is applied to a smart key (or fob key), battery efficiency is expected to be enhanced, but in the case of a vibration sensor IC, a device that receives operation power from the battery of the smart key Because of this, it causes continuous battery consumption. In particular, the current consumption of the vibration sensor varies according to the sensing strength (frequency, bandwidth), and depending on the situation, the current of the vibration sensor itself may be higher than the dark current of a general smart key. In particular, since it continuously consumes current (continuously consumes current while detecting vibration) regardless of the degree of movement, in the case of users who usually move with a smart key, a smart key to which a vibration sensor IC is not applied ( Rather than fob key), battery consumption may be faster (the Fob function is not blocked because there is vibration continuously, so the vibration sensor current + Fob basic dark current increases the current consumption), and improvement is needed.

Accordingly, according to an embodiment of the present invention, the LF receiving unit receives an LF signal including a command message indicating the opening or closing of the vehicle door from the vehicle, and the microcontrol unit, in response to the LF signal, By controlling the on (ON) and off (OFF) of the sensor unit that detects the movement of the key, the battery efficiency is improved. Here, the command message may be a message indicating a vehicle boarding or alighting of the user who owns the smart key.

According to another embodiment of the present invention, When the micro control unit determines that the LF signal includes the command message, it determines whether the location of the smart key is inside the vehicle, and the micro control unit determines that the location of the smart key is inside the vehicle. When determined, the sensor unit is controlled from ON to OFF to improve battery efficiency.

According to another embodiment of the present invention, when the micro-control unit determines that the command message is included in the LF signal, it determines whether the location of the smart key is outside the vehicle, and the location of the smart key is When it is determined that it is outside the vehicle, the sensor unit is controlled from OFF to ON to improve battery efficiency. Here, the micro-control unit determines whether the location of the smart key is inside the vehicle or outside the vehicle by comparing the reception intensity of the LF signal with a preset reference intensity.

According to another embodiment of the present invention, the micro control unit compares the LF signal with a reference strength to determine whether the smart key is located within an LF reception distance capable of LF communication with a vehicle, and the micro control unit When the smart key is located outside the LF reception distance, the LF receiver is controlled from ON to OFF to improve battery efficiency and the LF receiver is turned off. It is also possible to defend against hacking. Here, the micro control unit improves battery efficiency by controlling the LF receiver from OFF to ON only when the sensor unit detects the movement of the smart key.

According to another embodiment of the present invention, the micro control unit compares the LF signal with a reference strength to determine whether the smart key is located within an LF reception distance in which LF communication with a vehicle is possible, and the smart key is When located outside the LF reception distance, the sensing sensitivity of the sensor unit is adjusted to improve battery efficiency.

Here, adjusting the sensing sensitivity of the sensor unit includes: the sensor unit transfers measurement values of the movement of the smart key for a preset time to the micro control unit, and the micro control unit includes an average value of the measurement values When it is determined that the movement of the smart key is large and the movement of the smart key is small by comparing with the reference value, and when it is determined that the movement of the smart key is large, the sensing sensitivity of the sensor unit is adjusted from the first sensing sensitivity to the first sensing sensitivity. It may be controlled by a second sensing sensitivity smaller than the 1 sensing sensitivity.

Hereinafter, various embodiments of the present invention will be described in connection with the accompanying drawings. Various embodiments of the present invention may be modified in various ways and may have various embodiments. Specific embodiments are illustrated in the drawings and detailed descriptions thereof are provided. However, this is not intended to limit the various embodiments of the present invention to specific embodiments, it should be understood to include all changes and/or equivalents or substitutes included in the spirit and scope of the various embodiments of the present invention. In connection with the description of the drawings, similar reference numerals have been used for similar elements.

1 is a block diagram of a smart key according to an embodiment of the present invention.

Referring to FIG. 1, a smart key (or FOB Key) 100 according to an embodiment of the present invention controls each component in an input unit 110 and a smart key 100 capable of controlling a vehicle. A micro control unit (MCU) 120, a sensor unit 130 that detects the movement of the smart key 100, an LF receiver 130 and an RF transmitter 150 that communicates with the vehicle 200 ), a power supply unit 160 for supplying power to the components 120, 130, 140, and 150 in the smart key 100 may be included.

The configurations in the smart key 100 shown in FIG. 1 are only examples, and are not limited thereto. For example, although not shown in FIG. 1, the smart key 100 may be configured to further include a display unit that includes a touch function and provides various information to a user, a sound output unit that outputs sound, and the like.

The input unit 110 may be configured (or implemented) as a hard key installed on the exterior of the smart key 100, a dial, a display including a touch function, or the like. A user may input various control commands for the vehicle 200 through the input unit 110. For example, the user can lock or unlock the entire door of the vehicle 10 by pressing the hard key on the exterior of the smart key 100 (Remote Keyless Entry (RKE) function, Passive Keyless Entry (PKE) function, Welcome light function). ), open and close the drunk, start the engine, and make other beeps. The user's control command through the input unit 110 may be converted into an electrical signal and input to the MCU 120.

The sensor unit 130 detects the movement of the smart key 100 according to the control command input from the MCU 120, and detects the movement (e.g., the intensity of the movement, the amount of movement, the movement value). Etc.) can be converted into an electrical signal form and output to the MCU 120.

Although not shown, the sensor unit 130 is a vibration sensor (not shown) that detects vibration of the smart key 100, an acceleration sensor (not shown) that detects a change in acceleration of the smart key 100, and a smart key ( 100) may include at least one of a gyro sensor (not shown) for detecting a change in position. Therefore, the sensor unit 130 is detecting vibration of the smart key 100, shaking of the smart key 100, and detecting a position change of the smart key 100 according to the movement of the user holding the smart key 100. The movement of the smart key 100 including at least one may be detected.

In addition, in order to improve the battery efficiency (battery consumption) of the power supply unit 160, the sensor unit 130 is turned on or off in a specific situation (or a specific condition) according to a control command of the MCU 120. ) Can be. For example, the sensor unit 130 is turned off according to a control command of the MCU 120 when the user (or driver) holding the smart key 100 boards the vehicle, and conversely, the smart key 100 When a user (or a driver) having a vehicle gets off the vehicle, it may be turned on according to a control command of the MCU 120. In this way, the sensor unit 130 is turned off when the user (or driver) boards the vehicle, thereby minimizing the occurrence of dark current by the sensor unit 130.

In addition, the sensor unit 130 may adaptively adjust the sensing intensity (sensing sensitivity) according to a control command of the MCU 120 in an ON state (outside the vehicle). For example, if the movement of the user (or driver) holding the smart key 100 is small, the sensing strength (sensing sensitivity) of the sensor unit 130 is greatly adjusted, and the user holding the smart key 100 ( Alternatively, when there is a lot of movement of the driver), the sensing intensity (sensing sensitivity) of the sensor unit 130 is adjusted to be small. In the case of a large amount of movement of the user (or driver), the movement of the user (or driver) can be sufficiently sensed even if the sensing intensity (sensing sensitivity) is decreased, so normal operation is possible even when the sensing intensity (sensing sensitivity) is decreased. Do.

In this way, by adaptively adjusting the sensing strength (sensing sensitivity) to the sensor unit 130, the dark current caused by the sensor unit 130 can be minimized, thereby improving battery efficiency (battery consumption).

Adjusting the sensing strength (sensing sensitivity) of the sensor unit 130 may mean increasing or decreasing the sensing period (clock period, sensing frequency) of the sensor unit 130.

On (ON) and off (OFF) of the sensor unit 130 may be achieved by power supply and cut off of the power supply unit 160. For example, when the power supply unit 160 supplies power to the sensor unit 130 in response to a control command (power supply command) of the MCU 120, the sensor unit 130 is turned on, vice versa, the power supply unit When 160 cuts off the supply of power to the sensor unit 130 in response to a control command (power cut command) of the MCU, the sensor unit 130 may be turned off.

In addition, on (ON) and off (OFF) of the sensor unit 130 may be achieved by mode switching. For example, when a processor (not shown) in the sensor unit 130 switches from a wake up mode to a sleep mode in response to a control command (mode switching command) of the MCU, the sensor unit 130 ) Is off, and on the contrary, when the processor (not shown) in the sensor unit 130 switches from the sleep mode to the wake-up mode in response to a control command (mode change command) of the MCU, the sensor unit 130 Becomes ON.

The LF receiver 140 receives a low frequency (LF) signal from the vehicle communication unit 210 of the vehicle 200 through an LF antenna. Here, the LF (Low Frequency) signal may be a radio signal having a low frequency band of 120 kHz or more and 135 kHz or less.

The LF signal received from the vehicle includes a ride/unload command message indicating an opening/closing operation of the vehicle door and a confirmation request message requesting to confirm whether the location of the smart key 100 is inside or outside the vehicle 200.

The LF receiver 140 may include a memory for storing programs and data for performing modulation/demodulation, and a processor for modulating/demodulating an LF signal according to programs and data stored in the memory. The LF receiver 140 may receive an LF search signal periodically transmitted by the vehicle 200. Here, the search signal is the vehicle 200 in the vicinity of the vehicle 200 (within the LF communication range) in order to determine whether the smart key 100 is within the LF communication range (or LF reception distance) from the vehicle 10. ) Means an LF (Low Frequency) signal transmitted by.

In addition, the LF receiver 140 may be turned on or off in response to a control command of the MCU 120. The on (ON) and off (OFF) of the LF receiving unit 140, similar to the on (ON) and off (OFF) of the sensor unit 130, power supply / cut off or the mode of the processor in the LF receiving unit 140 It can be achieved through conversion.

The RF transmitter 150 (RFIC) transmits a radio frequency (RF) signal to the vehicle communication unit 210 of the vehicle 200. Here, the radio frequency (RF) signal may be a radio signal having an ultra-high frequency (UHF) of 315 MHz or more and 433 MHz or less.

The RF transmitter 150 may include a memory for storing programs and data for performing modulation/demodulation, and a processor for modulating/demodulating a radio frequency (RF) signal according to programs and data stored in the memory.

The RF transmitter 150 is a radio frequency (RF) including a communication port connecting the RF communication network and the MCU 120 of the smart key 100 and a transmitter for transmitting a radio frequency (RF) signal. It may include a communication interface.

The RF transmitter 150 may transmit a search response signal in response to the search signal of the vehicle 200 to the vehicle 200. The search response signal refers to an RF signal transmitted by the smart key 100 to the vehicle 200 so that the vehicle 200 can confirm that the smart key 100 has received the search signal from the vehicle 200.

The RF transmitter 150 may be turned on or off in a specific situation (or a specific condition) according to the control of the MCU 120. The on (ON) and off (OFF) of the RF transmission unit 160, similar to the on (ON) and off (OFF) of the sensor unit 130, power supply / cut off or a processor mounted in the RF transmission unit 150 It can be achieved through mode switching.

By the LF receiving unit 140 and the RF transmitting unit 150, the smart key 100 transmits a control signal related to the vehicle 200 or a procedure for confirming the unique identifier (ID) information. Low Frequency) signal or RF (Radio Frequency) signal can be transmitted and received.

The power supply unit 160 is a device that supplies power to the components 130, 140, and 150 in the smart key 100, and may include a battery (eg, a lithium ion battery). In addition, the power supply unit 160 may supply power to the sensor unit 130, the LF receiver 140, and the RF transmitter 150 or cut off the power supply according to a control command of the MCU 120.

The MCU 120 may include a processor and a memory that control operations of the components 110, 130, 140, 150, and 160 in the smart key 100. In addition, the MCU 120 may generate various data processing and control commands (control signals) related to electronic control of the smart key 100. In addition, the MCU 120 is based on the electrical signal input from the input unit 110, the door lock/unlock (RKE function, PKE function) of the vehicle 200, a control command (control signal) for locking/unlocking the drunk, and a warning sound. Can be created.

In addition, the MCU 120 is an on (ON) / off (OFF) operation of the sensor unit 130 in a specific situation (or a specific condition), the sensing strength of the sensor unit 130 (sensing sensitivity, for example, a sensing period) , Sensing frequency The period of the sensing clock or the frequency of the sensing clock) is adjusted, the on/off operation of the LF receiver 140 and the on/off operation of the RF transmitter 150 are controlled.

In addition, the MCU 120 controls on (ON) and off (OFF) of the sensor unit 130 according to the getting on/off command message transmitted from the vehicle. For example, the MCU 120 receives an LF signal including a ride command message indicating the opening of the vehicle door from the vehicle 200 through the LF receiver 140 and indicates that the smart key 100 is located inside the vehicle. Upon confirmation, the sensor unit 130 is turned off. In addition, when the MCU 120 receives an LF signal including an exit command message indicating the closing of the vehicle door from the vehicle 200 through the LF receiver 140 and confirms that the smart key 100 is located outside the vehicle, , The sensor unit 130 is turned on.

On the other hand, the vehicle 200 is a vehicle communication unit 210 that performs communication with the smart key 100, a vehicle control unit 220 (hereinafter, SMK ECU (Smart Key Electrical Control Unit)) that controls electronic parts or components in the vehicle. And a vehicle door control unit 230.

The vehicle communication unit 210 is capable of transmitting and receiving a smart key 100 and a low frequency (LF) signal, a low frequency (LF) communication unit 212, capable of transmitting and receiving a smart key 100 and a radio frequency (RF) signal. It may include a radio frequency (RF) communication unit 214.

The LF communication unit 212 in the vehicle 200 transmits an LF signal to the smart key 100 through an LF communication network. In addition, the LF communication unit 212 in the vehicle 200 may transmit a search signal to the smart key 100 according to a transmission period of the search signal. Here, the search signal is transmitted by the LF communication unit 212 in the vehicle 200 to the periphery (within a distance in which LF communication is possible) to determine whether the smart key 100 is within the range in which LF communication is possible from the vehicle 200. It means LF signal.

The RF communication unit 214 in the vehicle 200 receives an RF signal transmitted from the smart key 100 outside the vehicle 10 through an RF communication network. In addition, the RF communication unit 214 in the vehicle 200 may receive a search response signal from the smart key 100. Here, the search response signal means an RF signal transmitted from the smart key 100 to the vehicle 10 so that the vehicle 10 can confirm that the smart key 100 has received the search signal from the vehicle 10. .

In addition, the RF communication unit 214 in the vehicle 200 may further include an RF signal conversion module for demodulating an RF signal received through an RF communication interface into a control signal under the control of the vehicle controller 11.

When the LF communication unit 212 in the vehicle 200 transmits a search signal to the smart key 100 and the RF communication unit 214 in the vehicle 200 receives the search response signal from the smart key 100, the vehicle ( 200) and the smart key 100 perform a series of authentication processes, and when authentication is completed, the SMK ECU 220 unlocks various electronic components in the vehicle 200 so that the authenticated user can use it. For example, when authentication is completed, the SMK ECU 220 unlocks the steering wheel 27, unlocks the ignition button, unlocks the trunk of the vehicle 200, and unlocks the vehicle handle. The door lock can be released. A method of performing authentication between the vehicle 200 and the smart key 100 is a previously known technology, and thus a detailed description thereof will be omitted.

The SMK ECU 220 is a steering lock control unit that controls lock/unlock of the steering wheel, an ignition button control unit that controls lock/release of the ignition button that controls on/off of the vehicle 200, and locks/unlocks the vehicle door It may include a vehicle door control unit that controls the vehicle door control unit and a trunk control unit that controls locking/unlocking of the vehicle trunk. In addition, various types of locking/unlocking electronic components in the vehicle 200 are controlled depending on whether or not the smart key 100 is It may further include a control module. In FIG. 1, the vehicle door control unit 230 is shown to be provided outside the SMK ECU 220, but this is only to help understanding the description, and as described above, it may be provided inside the SMK ECU 220. Do.

In addition, the SMK ECU 220 generates a command message indicating getting on or off in response to an open or close signal of the vehicle door input from the vehicle door control unit 230, and configures this as an LF signal to provide the LF communication unit 212. It is transmitted to the smart key 100 through.

In addition, when the SMK ECU 220 confirms reception of an RF signal including a ride command response message to the command message from the smart key 100, the SMK ECU 220 generates a location confirmation request message requesting the location of the smart key 100 Then, it is configured as an LF signal and transmitted to the smart key 100 through the LF communication unit 212.

In addition, the SMK ECU 220 may include a memory that stores programs and data for controlling electric components in the vehicle 200, and a processor that generates a control signal according to programs and data stored in the memory.

The SMK ECU 220 may receive a signal transmitted from the smart key 100 from the vehicle communication unit 210 and control the vehicle to perform an operation corresponding thereto.

2 is a flow chart of a message exchanged between a smart key and a vehicle according to an embodiment of the present invention.

Referring to FIG. 2, in the method of controlling a smart key according to an embodiment of the present invention, in order to reduce power (dark current) consumed by the sensor unit 130, the sensor unit 130 is not always turned on, but from the vehicle. It is turned on or off based on the transmitted boarding/disembarkation command message. That is, ON/OFF (OFF) of the sensor unit 130 embedded in the smart key is switched by triggering a boarding/alighting command message transmitted from the vehicle 200.

Specifically, the SMK ECU 220 generates a command message indicating getting on or off according to the vehicle door open or close signal input from the vehicle door controller 230, and configures this as an LF signal and transmits it to the MCU 120. (S22).

Subsequently, the MCU 120 generates a command response message to the command message included in the LF signal, configures it as an RF signal, and transmits it to the SMK ECU 220 of the vehicle (S24).

Subsequently, upon receiving the command response message, the SMK ECU 220 generates a location confirmation request message, configures it as an LF signal, and transmits it to the MCU 120 (S26).

Subsequently, the MCU 120 configures a position check response message to the position check request message as an RF signal and transmits it to the SMK ECU 220.

On the other hand, in S26, when the MCU 120 receives the location confirmation request message, in response to this, the location of the smart key 120 is determined, and according to the determined location, when the smart key 100 is located outside the vehicle, When the sensor unit 130 is turned on and the smart key 100 is located inside the vehicle, the sensor unit 130 is turned off.

The opening of the vehicle door may mean getting on or off by a user (driver). Likewise, closing of the vehicle door may mean getting on or off by a user (driver).

Therefore, in order to accurately determine the getting on and off of the user (driver), in addition to receiving the ride or getting off command message, the location of the smart key 100 held by the user (or driver) is inside the vehicle (indoor) or outside (outdoor). The process of determining cognition must be involved.

The MCU 120 may determine the location of the smart key 100 by comparing the reception strength of the LF signal including the location confirmation request message with a preset reference strength.

The reference strength is a reference value set in advance to determine the location of the smart key 100, and may include, for example, a first reference strength and a second reference strength set smaller than the first reference strength.

When the reception strength of the LF signal is greater than or equal to the first reference strength, it is determined that the smart key 100 is located inside the vehicle (inside the vehicle). When the reception strength of the LF signal is less than the first reference strength and more than the second reference strength, the smart key 100 is located outside the vehicle (outside the vehicle) within the range (LF reception distance) in which LF communication with the vehicle is possible. Discriminate. If the reception strength of the LF signal is less than the second reference strength, it may be determined that the smart key 100 is located outside the range in which LF communication with the vehicle is possible (LF reception distance).

Hereinafter, a method of controlling a smart key according to an embodiment of the present invention will be described in detail based on the message flow shown in FIG. 2.

3 is a flowchart illustrating a method of controlling a smart key according to an embodiment of the present invention.

Referring to FIG. 3, first, in step S312, a method of controlling a smart key according to an embodiment of the present invention starts from a state in which the sensor unit 130 and the LF receiver 140 are always on.

Next, in step S314, the MCU 120 compares the reception strength of the LF signal transmitted from the vehicle with a preset reference strength, and whether the smart key 100 is within the range (LF reception distance) in which LF communication with the vehicle is possible. Determine if you are outside. For example, if the reception strength of the LF signal is less than the first reference strength and more than the second reference strength, as shown in FIG. 4, it is determined that the smart key 100 is located within the LF reception distance outside the vehicle, If the reception strength of the LF signal is less than the second reference strength, it is determined that the smart key 100 is located outside the LF reception distance, as shown in FIG. 5. If the smart key 100 is located within the LF reception distance, the process proceeds to step S316, and if the smart key 100 is located outside the LF reception distance, the process proceeds to step S326. First, a description will be given from step S326.

In step S326, when it is determined that the smart key 100 is located outside the LF reception distance, the LF receiver 140 is switched from ON to OFF in response to a control command from the MCU 120.

Subsequently, in step S328, the MCU 120 adjusts the sensing sensitivity of the sensor unit 130 in order to minimize the dark current generated by the sensor unit 130. For example, the sensor unit 130 transmits the measured values of the movement of the smart key 100 for a preset time to the MCU 120. Then, the MCU 120 calculates the average value of the measured values, compares it with a preset reference value, and determines that the amount of movement of the user (or driver) holding the smart key 100 is large if the average value is greater than the reference value. , A control command instructing to lower a second sensing sensitivity lower than the first default first sensing sensitivity is generated and transmitted to the sensor unit 130. Then, the sensor unit 130 changes from the first sensing sensitivity to the second sensing sensitivity in response to the control command of the MCU 120. Here, the change of the sensing sensitivity means a change of an internal sensing period, a sensing frequency, or a frequency of a sensing clock. Although not shown, in order to change the sensing sensitivity, for example, the sensor unit 130 may include a clock generator and a multiplexer that generate a plurality of clocks having different sensing frequencies. When a plurality of clocks are input to the multiplexer, the multiplexer may change the sensing sensitivity by using a control command of the MCU 120 as a selection signal to select among the plurality of clocks having a sensing frequency corresponding to the second sensing sensitivity. Meanwhile, even if the sensing sensitivity is lowered from the first sensing sensitivity to the second sensing sensitivity, there is no problem in the sensing operation of the sensor unit 130. Since a sufficient measurement result can be secured when there is a large amount of movement of the smart key 100, it is not unreasonable to detect the movement of the smart key 100 even with the reduced second sensing sensitivity. This change in sensing sensitivity is performed periodically. Therefore, after a certain period of time, if the average value of the measured values of the movement of the smart key 100 falls below the reference value, it is determined that the movement of the user (or driver) holding the smart key 100 has decreased, and the sensor unit 130 restores the original initially defaulted first sensing sensitivity according to the control command of the MCU 120, and by doing so, it is possible to control the small movement of the smart key 100 not to be detected as the second sensing sensitivity. have.

Subsequently, in step S330, the MCU 120 determines whether the smart key 100 moves using the sensor unit 130 whose sensing sensitivity is adjusted. When the movement of the smart key 100 is confirmed, the first step S312 goes back to the LF receiving unit 140 to switch to the ON state, and if the movement of the smart key 100 is not confirmed, the LF receiving unit 140 Maintains the OFF state. That is, according to steps S326, S328, and S330, by switching the LF receiver 140 from off to on only when the movement of the smart key 100 is detected outside the LF reception distance, the LF receiver ( 140) can reduce battery consumption, and when the movement of the smart key 100 is not detected, the LF receiver 140 is turned off, thereby preventing hacking such as RSA.

Again, returning to step S314, if it is determined that the smart key 100 is within the LF reception distance, in step S316, whether the MCU 120 has received a ride command message from the vehicle 200 (or SMK ECU 220) Confirm. If the ride command message is not received, the process returns to the previous step S314.

When the reception of the ride command message is confirmed, in step S318, the MCU 120 compares the reception strength of the LF signal including the ride command message transmitted from the vehicle with the reference strength, and the location of the smart key 100 is shown in FIG. 6 As shown in, it is checked whether it is inside the vehicle (inside the vehicle). As described above, since it is not possible to determine whether the user (or driver) rides only by confirming receipt of the ride command message, it is necessary to check whether the smart key 100 is located inside the vehicle (inside the vehicle). In the positioning method, if the reception strength of the LF signal is greater than or equal to the first reference strength described above, it is determined that the smart key 100 is located inside the vehicle. When the location of the smart key 100 is outside the vehicle, it returns to the previous step S316.

When it is determined that the smart key 100 is located inside the vehicle, in step S320, the sensor unit 130 is switched from ON to OFF according to the control command of the MCU 120. In this way, when the smart key 100 is located inside the vehicle, the sensor unit 130 is turned off, thereby reducing battery consumption by the sensor unit 130.

Subsequently, in step S322, it is determined whether the MCU 120 has received the getting off command message from the vehicle 200 (or SMK ECU 220). If it is confirmed that the getting off command message has not been received, the sensor unit 130 returns to the previous step S320 and keeps the off state (OFF), thereby continuously reducing battery consumption.

When the MCU 120 confirms the reception of the getting off command message, the MCU 120 compares the reception strength of the LF signal including the get off command message with the reference strength in step S324, and the smart key 100 is located outside the vehicle. Judge whether or not. As described above, since it is not possible to determine whether the user (or driver) holding the smart key 100 has actually got off only by confirming the reception of the alighting command message, it is necessary to determine whether the smart key 100 is located outside the vehicle. There is. The method of determining whether the smart key 100 is located outside the vehicle is similar to the determination method of step S318 described above. For example, if the reception strength of the LF signal including the getting off command message is less than the first reference strength and more than the second reference strength, it is determined that the smart key 100 is located outside the vehicle.

When it is determined that the smart key 100 is located outside the vehicle and it is determined that the user (or driver) has completely alighted, it returns to the first step S312, and the sensor unit 130 responds to the control command of the MCU 120 Accordingly, it is switched from OFF to ON.

As described above, the present invention is different from the prior art, in which the sensor unit 130 is always turned on, the sensor unit 130 is turned off when riding a vehicle, thereby blocking the occurrence of dark current as well as the sensor unit ( By reducing battery consumption by 130), battery efficiency in the power supply unit 160 may be improved. In addition, outside the LF reception distance, the sensing strength (sensing sensitivity) of the sensor unit 130 is adaptively adjusted to minimize the dark current generated by the sensor unit 130, which also improves battery efficiency. Here, it should be noted that the state in which the sensing strength (sensing sensitivity) of the sensor unit 130 is adjusted is maintained not only outside the LF reception distance, but also within the LF reception distance. Therefore, in the understanding of the present invention, the improvement of battery efficiency by adjusting the sensing strength (sensing sensitivity) should not be understood as an effect that can be obtained only outside the LF reception distance. In addition, although FIG. 3 shows that the step of performing the sensing sensitivity adjustment (S328) is performed only outside the LF reception distance, the present invention is not limited thereto, and may be performed even after the smart key 100 enters the LF reception distance. . However, since the sensor unit 130 is turned off in the vehicle interior, it is not necessary to adjust the sensing sensitivity in the vehicle interior.

In the above, the present invention has been described centering on the embodiments, but these are only examples, and do not limit the present invention, and those of ordinary skill in the field to which the present invention pertains should not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications that are not illustrated in are possible. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Claims (16)

Including an LF receiver that receives a low frequency (LF) signal from a vehicle, an RF transmitter that transmits a radio frequency (RF) signal to the vehicle as a response to the LF signal, a sensor unit that detects a user's movement, and a micro control unit In the control method of the smart key,
Receiving, by the LF receiver, an LF signal including a command message indicating opening or closing of a vehicle door from the vehicle; And
Controlling, by the micro-control unit, on (ON) and off (OFF) of the sensor unit detecting movement of the smart key in response to the LF signal;
Smart key control method comprising a. The method of claim 1, wherein the command message,
A method of controlling a smart key that is a message indicating a vehicle boarding or alighting of a user who owns the smart key. In claim 1, the step of controlling the sensor unit on (ON) and off (OFF),
Determining, by the micro-control unit, whether the position of the smart key is inside the vehicle when it is confirmed that the command message is included in the LF signal; And
When the micro-control unit determines that the position of the smart key is inside the vehicle, controlling the sensor unit from ON to OFF
Smart key control method comprising a. In claim 1, the step of controlling the sensor unit on (ON) and off (OFF),
Determining whether the position of the smart key is outside the vehicle when the micro control unit determines that the command message is included in the LF signal; And
When the micro-control unit determines that the position of the smart key is outside the vehicle, controlling the sensor unit from OFF to ON
Smart key control method comprising a. In claim 3 or 4, the determining step,
The method for controlling a smart key is the step of determining, by the micro-control unit, whether the position of the smart key is inside the vehicle or outside the vehicle by comparing the reception intensity of the LF signal with a preset reference intensity. In claim 1,
Determining, by the micro control unit, whether the smart key is located within an LF reception distance in which LF communication with a vehicle is possible by comparing the LF signal with a reference strength; And
Controlling, by the micro control unit, the LF receiver from ON to OFF when the smart key is located outside the LF reception distance;
The method of controlling a smart key that further comprises. In paragraph 6,
Controlling the LF receiver from off to on only when the micro control unit detects the movement of the smart key by the sensor unit
The method of controlling a smart key that further comprises. In claim 1,
Determining, by the micro control unit, whether the smart key is located within an LF reception distance in which LF communication with a vehicle is possible by comparing the LF signal with a reference strength; And
If the micro-control unit, the smart key is located outside the LF reception distance, adjusting the sensing sensitivity of the sensor unit
The method of controlling a smart key that further comprises. The method of claim 8, wherein adjusting the sensing sensitivity of the sensor unit,
Transmitting, by the sensor unit, measurement values obtained by measuring movement of the smart key for a preset time to the micro control unit;
Determining, by the micro-control unit, a case where the movement of the smart key is large and the movement of the smart key is small by comparing the average value of the measured values with a reference value; And
If the micro-control unit determines that the movement of the smart key is large, controlling the sensing sensitivity of the sensor unit from the first sensing sensitivity to a second sensing sensitivity smaller than the first sensing sensitivity;
The method of controlling a smart key comprising a. An LF receiver receiving an LF signal including a command message indicating the opening or closing of the vehicle door from the vehicle;
An RF transmitter for transmitting an RF signal for the LF signal to the vehicle;
A sensor unit for detecting a user's movement; And
A micro control unit that generates a control command for controlling ON and OFF switching of the sensor unit in response to the LF signal
Smart key containing. The method of claim 10, wherein the LF receiver,
The smart key to receive the command message indicating the user's vehicle getting on or off the vehicle. The method of claim 10, wherein the micro control unit,
When it is confirmed that the command message is included in the LF signal, it is determined whether the location of the smart key is inside the vehicle, and when it is determined that the location of the smart key is inside the vehicle, the sensor unit is turned on. A smart key that generates a control command for controlling off (OFF). The method of claim 10, wherein the micro control unit,
When it is confirmed that the command message is included in the LF signal, it is determined whether the location of the smart key is outside the vehicle, and when it is determined that the location of the smart key is outside the vehicle, the sensor unit is turned on from OFF. A smart key that generates a control command for controlling (ON). The method of claim 10, wherein the micro control unit,
By comparing the LF signal and the reference strength, it is determined whether the smart key is located within an LF reception distance in which LF communication with a vehicle is possible, and when the smart key is located outside the LF reception distance, the LF receiver is turned on. A smart key that generates a control command for controlling from to off. The method of claim 10, wherein the micro control unit,
Comparing the LF signal with a reference strength to determine whether the smart key is located within an LF reception distance in which LF communication with a vehicle is possible, and when the smart key is located outside the LF reception distance, adjusting the sensing sensitivity of the sensor unit The smart key is to generate a control command for. The method of claim 15, wherein the micro control unit,
From the sensor unit, measurement values obtained by measuring the movement of the smart key for a preset time are received, and the average value of the measured values and the reference value are compared to determine when the movement of the smart key is large and the movement of the smart key is small. When it is determined that the movement of the smart key is large, the smart key generates a control command for controlling the sensing sensitivity of the sensor unit from the first sensing sensitivity to a second sensing sensitivity smaller than the first sensing sensitivity. .

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