JP2005146708A - Keyless entry system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a keyless entry system allowing to unlock a door automatically by detecting a portable key owner in behavior of door opening. <P>SOLUTION: This keyless entry system is composed of a portable key for transmitting an ID code as a radio signal intermittently, a reception circuit for receiving the radio signal from the portable key and outputting a signal corresponding to reception signal strength, a means for detecting reception strength change rate of the signal outputted from the reception circuit, a microcomputer, a locking/unlocking mechanism driving circuit, and a locking/unlocking mechanism. Consequently, the door can be automatically unlocked by detecting that the reception strength change rate of the signal exceeds a predetermined value and unlocking and operating a locking/unlocking control driving circuit to unlock. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a wireless locking / unlocking control device (hereinafter referred to as a keyless entry system) applied to a vehicle, a house door, and the like.

  As a conventional keyless entry system, the mobile key user manually operates a button provided on the mobile key to transmit the ID code from the mobile key every time the door is unlocked and unlocked, and receives the ID code to the door side communication device. In addition, there is a method in which the door is unlocked and unlocked when it is determined that the received ID code is permitted to unlock the door, while the portable key and the communication device on the door side are always at predetermined time intervals. Communication is performed, and when the mobile key user approaches the vicinity of the door, the door side communication device can receive the ID code transmitted from the mobile key, and the received ID code is permitted to unlock the door. There is also a method in which the door is automatically unlocked when it is determined that there is. The method of automatically unlocking the door eliminates the need for the mobile key owner to perform a special operation for unlocking, and is superior in operability (see, for example, Patent Document 1). In the apparatus described in Patent Document 1, means for intermittently transmitting a transmission request command to the vehicle side, and reception confirmation means for confirming reception of a code signal returned from the portable key in response to the transmission request command And a lock control means for locking the vehicle door on condition that the reception of the code signal is interrupted. In addition, since it also has an unlocking control means for unlocking the vehicle door when a code signal is received after locking, the person holding the portable key does not need to perform a special unlocking operation and automatically It is possible to lock and unlock. However, in this conventional example, when the person who has the portable key is near the door, the vehicle door and the portable key can always communicate code signals, so the vehicle door is always unlocked. Keeping the door unlocked at all times increases the risk of vehicle theft and the like, so it is necessary to re-lock the door by some means for a certain period of time. As a conventional example in which this measure is described, after the unlocking operation of the vehicle door based on the signal received from the portable key, the timer is operated, and the door is re-locked when the door is not opened within the specified time. A keyless entry system including means is described (for example, see Patent Document 2).

JP-B-5-3509 (page 2-5, Fig. 1-2) Japanese Examined Patent Publication No. 7-47907 (page 3-4, FIG. 5)

  However, there has been no keyless entry system that can cope with any action of a person who has a portable key. For example, if the owner of the portable key is re-locked after a specified time even though the owner of the portable key is near the door using the technique of Patent Document 2, the owner of the portable key next opens the door. Need to unlock again. In this case, the door-side communication device has no means for knowing that the portable key owner is opening the door, and therefore cannot be unlocked automatically. Therefore, since the holder of the portable key needs to perform a special operation such as pressing a re-unlock button installed on the portable key in order to unlock the door again, it is inferior in usability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a keyless entry system that can cope with all actions of a person who possesses a portable key, for example, when the owner of the portable key is near a door. It is to provide a keyless entry system that automatically detects the movement of the portable key owner when the door is opened and unlocks the door automatically.

In order to achieve the above object, the gist of the present invention is a portable key that intermittently transmits an ID code as a radio signal, and reception that receives a radio signal from the portable key and outputs a signal corresponding to the received signal strength. A keyless entry system comprising a circuit, means for detecting a rate of change in received intensity of the signal corresponding to the received signal intensity output from the receiving circuit, a microcomputer, a locking / unlocking mechanism driving circuit, and a locking / unlocking mechanism The door can be automatically unlocked by detecting that the rate of change in the received signal strength according to the received signal strength exceeds a predetermined value and unlocking the unlocking control drive circuit. .

In addition, since the portable key is attached to the user's arm, it is easy to determine the movement of the user to bring the arm close to the door to open the door, and the door can be unlocked reliably. .

A portable key that intermittently transmits an ID code as a wireless signal; an antenna that receives the wireless signal; and a receiving circuit that receives the wireless signal from the portable key and outputs a signal corresponding to the received signal strength. A keyless entry system for a vehicle comprising means for detecting a rate of change in received intensity of the signal output from the receiving circuit, a microcomputer, a locking / unlocking mechanism driving circuit, and a locking / unlocking mechanism, wherein the antenna is connected to the vehicle. By installing it in the door knob, it becomes easy to determine the movement of the user wearing the portable key close to the door to open the door, and the door can be reliably unlocked.

As described above, according to the present invention, a keyless entry system with better operability can be provided for the unlocking of a portable key user.

In addition, since the mobile key is attached to the arm, it is easy to determine the movement of the user to bring the arm close to the door to open the door, and the door can be unlocked reliably.

In addition, when the present invention is used in a vehicle keyless entry system, the receiving antenna is installed in the door knob of the vehicle, so that the movement of the portable key closer to the door knob can be easily discriminated, and the door can be reliably unlocked. I can do it.

A keyless entry system according to an embodiment of the present invention will be described.
The present invention can be applied to all keyless entry systems that control entry / exit into a room, such as a vehicle door and a front door of a house. The following is an example applied to a keyless entry system for a vehicle door. FIG. 1 is a block diagram of a keyless entry system of the present invention. The keyless entry system of the present invention includes a portable key 100 and a door side locking / unlocking control unit 110 that performs locking / unlocking. In this embodiment, the portable key 100 is a bracelet type that can be attached to the arm, and is attached to the wrist on the side where the user operates the door knob when opening the door. Although it is attached to the wrist in order to obtain the effect of the present invention described below most, it is not limited to the wrist attachment, and may be attached to the chest or the like. In other words, the effect of the present invention can be obtained even if it is carried in a pocket of clothes as in the conventional portable key.
The portable key 100 includes a microcomputer 104 for controlling, an ID code memory 105 for storing a unique ID code, a modulation circuit 103 for modulating the ID code, and the modulated ID code as a transmission signal. The transmission circuit 102 is configured to output and an antenna 101 for transmitting a transmission signal by radio waves.
On the other hand, the locking / unlocking control unit 110 is mounted on the vehicle side, receives a transmission signal transmitted from the portable key 100, determines validity / invalidity of the ID code, and locks / unlocks the locking mechanism of the vehicle door. Is what you do.
The locking / unlocking control unit 110 includes a microcomputer 114 for performing control, an ID code memory 115 for storing a unique ID code, an antenna 111 for receiving radio waves from the portable key 100, and detection / reception of received signals. A receiving circuit 112 for performing amplification, a demodulating circuit 113 for demodulating an ID code from a received signal, a received intensity change rate detecting means 116 for detecting a time change rate of received intensity, and a mechanism for locking or unlocking The locking / unlocking mechanism 118, the locking / unlocking mechanism driving circuit 117 for driving the locking / unlocking mechanism 118, and the door opening sensor 119 are configured.
The reception intensity change rate detection means 116 constantly monitors the time change of the reception signal intensity output from the reception circuit 112. If the transmission output of the portable key 100 is constant, the radio wave reception intensity increases in inverse proportion to the square of the distance. Therefore, when the portable key 100 approaches the antenna 111, the reception signal of the reception circuit 112 according to the square of the distance. Strength increases. Considering an operation in which the user extends the arm with the portable key 100 attached to the doorknob to open the vehicle door, the time variation rate of the received signal strength is greatest when the antenna 111 is installed in the doorknob or in the vicinity thereof. Therefore, in the present embodiment, the antenna 111 is installed inside the door knob.
When the reception intensity change rate detection means 116 detects an increase in reception intensity due to an operation in which the user extends the arm wearing the portable key 100 to the door knob, it generates an interrupt to the microcomputer 114. Note that an interrupt occurs when an increase in reception strength is detected only in an interrupt enabled state, which will be described later, and no interrupt occurs even when an increase in reception strength is detected in an interrupt disabled state. The microcomputer 114 can know that the arm has extended to the doorknob by the occurrence of this interruption. Even if the antenna 111 is installed at a place other than the door knob, the effect of the present invention can be obtained.
The locking / unlocking mechanism drive circuit 117 switches between locking / unlocking of the locking / unlocking mechanism 118 according to a control signal from the microcomputer 114. The door opening sensor 119 is a sensor that detects that the vehicle door has been opened, and the microcomputer 114 can know the opening of the vehicle door from the signal of the door opening sensor 119.

2 to 4 are flowcharts for explaining the flow of the operation of the program according to the embodiment of the present invention. 2 shows the operation of the microcomputer 104 of the portable key 100, and FIGS. 3 and 4 show the operation of the microcomputer 114 in the locking / unlocking control mechanism 110.
Hereinafter, an example in which the locked vehicle door is opened when the user gets on will be described with reference to FIGS. 1 to 4.
The portable key 100 worn by the user transmits an ID code in S201 as shown in the flowchart of FIG. Although the transmission interval is not particularly defined, transmission is performed every 0.1 seconds in this embodiment. The transmission interval is controlled by the microcomputer 104, and the transmitted ID code is stored in the ID code memory 105, and is an ID code unique to this portable key. The microcomputer 104 sends the read ID code to the modulation circuit 103. The modulation circuit 103 modulates the ID code with the carrier frequency. The modulated ID code is sent to the transmission circuit 102, power necessary for transmission is supplied by the transmission circuit 102, and is transmitted as a radio wave by the antenna 101.

The locking / unlocking control unit 110 in FIG. 1 is always in a reception waiting state when the user is not in the vicinity of the vehicle. FIG. 3 shows a reception confirmation operation for each time of the microcomputer 114. The reception confirmation interval is not particularly defined, but in this embodiment, reception confirmation is performed every 0.2 seconds. The reception confirmation interval is controlled by the microcomputer 114.
The radio wave received by the antenna 111 is detected and amplified by the receiving circuit 112, and an analog signal modulated at the carrier frequency is obtained. A signal corresponding to the intensity of the received radio wave is sent to the reception intensity change rate detecting means 116, while the demodulation circuit 113 demodulates the ID code from the modulated analog signal. The microcomputer 114 compares the demodulated ID code with the ID code stored in its own ID code memory 115. If the microcomputer 114 determines that the ID code is permitted to be unlocked, the microcomputer 114 sends a lock / unlock mechanism drive circuit 117 to the microcomputer 114. Give an order to unlock.
Next, FIG. 3 will be described. In FIG. 3, the status flag is 1 in the unlocked state, and normally in the locked state, the status flag is 0 (however, the door is not opened after being unlocked once and the locked state is reached after a specified time has elapsed. However, the status flag = 1) is a flag for managing the locking / unlocking status.
In S301 of FIG. 3, it is determined whether or not the ID code for which unlocking is permitted has been received. If the user is sufficiently away from the vehicle and the radio wave from the portable key 100 does not reach, the process proceeds to S315. The interrupt prohibition process is performed at S316, and the process of setting the status flag to 0 is performed at S316. However, when the vehicle door is originally locked, the state does not change and does not particularly make sense. (The initial value of the interrupt state is prohibited and the initial value of the status flag is 0, but this is not shown). Even in the determination of the condition in S317, since the door is in the locked state, no processing is performed as it is, and the series of operations ends.
Next, a case where the user approaches the vehicle and the locking / unlocking control unit 110 can receive a transmission signal from the portable key 100 will be described. If it is determined in S301 in FIG. 3 that an ID code permitted to be unlocked has been received, it is determined in S302 that the door is locked, and a status flag is viewed in S303. Since the status flag has an initial value of 0, the process proceeds to S304 and S305, and the microcomputer 114 of the locking / unlocking control unit 110 in FIG. 1 issues an unlocking command to the locking / unlocking mechanism drive circuit 117 and performs processing for setting the status flag to 1. . The locking / unlocking mechanism drive circuit 117 drives the locking / unlocking mechanism 118 in the unlocking direction, and the vehicle door is unlocked. After performing the unlocking operation in S304 in FIG. 3, the status flag is set to 1 in S305, indicating that the unlocked state is set. In S306, a timer is started. This timer is provided in the microcomputer 114 (not shown), and is used for defining the unlocked holding time. Although there is no particular limitation on the holding time in the unlocked state, 10 minutes is set as the specified value in the present embodiment. Therefore, as long as the ID code from the portable key 100 is continuously received for 10 minutes after unlocking the vehicle door, the process proceeds from S302 to S307, and if the door has not been avoided yet (the door opening is shown in FIG. 1). The process proceeds to S311. In S311, it is determined whether or not the timer has reached the specified time of 10 minutes. If the specified time has not been reached, nothing is performed as it is and the series of operations ends. This process flow is repeated until the specified time is reached.
A case where the user opens the vehicle door within 10 minutes of the specified time will be described. If it is detected in S307 in FIG. 3 that the door has been opened, the interrupt disabled state is set in S308, and the status flag is set to 0 in S309. Since the status flag was set to 1 in S305, it returns to 0 here. However, since the interrupt is not enabled, there is no change. Further, since the door has been opened within the specified time, the timer is stopped in S310, and the series of door opening operations ends.

Next, the case where the specified time has passed before the vehicle door is avoided and the vehicle door is once locked, which is a feature of the present invention, will be described. When the vehicle door is unlocked in S304 of FIG. 3 and the specified time reaches 10 minutes without being opened, the process proceeds from S311 to S312 to stop the timer, and then locks in S313. 1 is sent from the microcomputer 114 of FIG. 1 to the locking / unlocking mechanism driving circuit 117, and the locking / unlocking mechanism driving circuit 117 drives the locking / unlocking mechanism 118 in the locking direction, and the vehicle door is locked. After locking in S313 in FIG. 3, the interrupt is permitted in S314, and the locking operation is terminated.
This state is, for example, a state in which a user who has a portable key is near the vehicle but does not get into the vehicle immediately and is performing other work. In this case, in order to avoid the risk of a person other than the user entering the vehicle, the door is automatically locked after the lapse of the specified time.
After locking, even if the user is in the vicinity of the vehicle and can receive the ID code, the status flag remains 1, so the determination of No is made in S303 of FIG. The routine is repeatedly terminated. Therefore, the vehicle door is not unlocked.

Next, a case will be described in which the user extends the arm with the portable key 100 attached to the door knob in order to open the vehicle door. When the arm is extended to the doorknob, the distance between the portable key 100 and the antenna 111 installed in the doorknob approaches, and the radio wave intensity received by the antenna 111 is inversely proportional to the square of the distance between the portable key 100 and the antenna 111. Increase rapidly. Therefore, a signal corresponding to an increase in reception strength is supplied from the reception circuit 112 to the reception strength change rate detection means 116. When the reception intensity change rate detection means 116 detects an increase in reception intensity, it sends an interrupt signal to the microcomputer 114, and the microcomputer 114 determines that the user has extended his arm to the door knob by the generation of the interrupt signal.
FIG. 4 explains the flow of processing when an interrupt occurs. Unlocking is performed in S401, and a timer is started in S402. Thus, the vehicle door is unlocked again, and the user can open the door and get on the vehicle without performing any special operation.
If the hand reaches the door knob and the vehicle door is unlocked but does not open, the timer again waits for opening for a specified time of 10 minutes. If the door is opened within 10 minutes, the unlocking operation is completed. If the door is not opened for more than 10 minutes, the door is locked again.

Next, locking will be described. The case of locking means that the user leaves the vehicle and the locking / unlocking control unit 110 cannot receive the ID code from the portable key 100.
When the ID code cannot be received, the process proceeds from S301 to S315 in FIG. 3, interrupt is prohibited in S315, and the status flag is returned to 0 in S316. This processing is necessary when the user approaches the vehicle and the door of the vehicle is unlocked, but the user does not operate the door and leaves the vehicle as it is. In S317, it is determined whether or not the vehicle door is locked. When the vehicle door is unlocked, locking is performed in S318, and the series of locking operations is completed. Thereafter, the ID code reception waiting state is entered until the user wearing the portable key again approaches the vehicle.

As described above, the keyless entry system according to the present embodiment employs the radio wave reception intensity change rate as a determination for unlocking the door. Unlocking can be performed. This eliminates the need for the user to perform a special operation for unlocking, so that it is possible to provide a keyless entry system that is easy to use and highly secure.
In this embodiment, a description is given of using the change in reception strength for unlocking a vehicle door that has been locked once after a specified time has passed. Of course, changes in intensity may be used.

  In the present embodiment, radio waves are used as communication means. However, the present invention can be adopted as communication means that can communicate wirelessly in a non-contact manner such as light and sound.

  In the present embodiment, the portable key is attached to the arm on the side where the user opens the door. However, if the rate of change in the reception intensity of the radio wave can be detected, other parts of the body such as feet and chest It does not matter if it is attached to.

  In the present embodiment, the keyless entry system for vehicle doors has been described. However, the present invention may be applied to entrances / exits of facilities and doors of houses.

  In addition to the unlocking operation as a keyless entry system, it is also possible to detect the rate of change in received radio wave intensity and use it as a switch for automatic door opening, lighting device lighting, air conditioner operation, and the like.

It is a block diagram of the keyless entry system which shows one embodiment of this invention. It is a figure which shows operation | movement of the portable key which shows one embodiment of this invention. It is a figure which shows operation | movement of the locking / unlocking control part which shows one embodiment of this invention. It is a figure which shows the interruption processing operation | movement of the locking / unlocking control part which shows one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Portable key 101 Antenna 102 Transmission circuit 103 Modulation circuit 104 Microcomputer 105 ID code memory 110 Locking / unlocking control device 111 Antenna 112 Reception circuit 113 Demodulating circuit 114 Microcomputer 115 ID code memory 116 Reception intensity change rate detection means 117 Locking / unlocking mechanism driving Circuit 118 Locking / unlocking mechanism 119 Door opening sensor

Claims (3)

A portable key that intermittently transmits an ID code as a wireless signal, a receiving circuit that receives a wireless signal from the portable key and outputs a signal corresponding to the received signal strength, and the received signal that is output from the receiving circuit A keyless entry system comprising means for detecting a rate of change in received signal strength according to strength, a microcomputer, a locking / unlocking mechanism drive circuit, and a locking / unlocking mechanism, and a change in received signal strength according to the received signal strength A keyless entry system characterized in that when the rate exceeds a predetermined value, the unlocking mechanism driving circuit is unlocked. The keyless entry system according to claim 1, wherein the portable key is mounted on a user's arm. A portable key that intermittently transmits an ID code as a wireless signal; an antenna that receives the wireless signal; a receiving circuit that receives a wireless signal from the portable key and outputs a signal according to received signal strength; A keyless entry system for a vehicle comprising means for detecting a rate of change in received intensity of the signal output from the receiving circuit, a microcomputer, a locking / unlocking mechanism driving circuit, and a locking / unlocking mechanism, and the antenna is installed in a door knob of the vehicle The keyless entry system according to claim 1, wherein the keyless entry system is installed in the system.

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