JP2008106577A - Passive keyless entry system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a passive keyless entry system which can prevent unintended locking from being performed due to poor communication etc. when a portable device gets away from a vehicle. <P>SOLUTION: This passive keyless entry system is equipped with a control portion 10 which transmits a request signal with a predetermined time period from a vehicle-side device 2 provided in the vehicle, which transmits an answer signal when the portable machine 5 receives a request signal, and which performs prescribed control when the vehicle-side device receives or does not receive the answer signal. The portable machine is equipped with a portable-machine control portion 20 for detecting the intensity of the request signal transmitted from the vehicle-side device. When the intensity of the request signal exceeds a predetermined value, the portable-machine control portion immediately transmits a signal including information to that effect. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a passive keyless entry device that locks and unlocks a door by performing wireless communication between a portable device and a vehicle-side device, and particularly locks the door when the portable device is separated from a vehicle by a predetermined distance or more. The present invention relates to a passive keyless entry device.

  In passive keyless entry devices, vehicles such as automobiles are equipped with a vehicle-side device that performs wireless communication with a portable device carried by the driver, and locks and unlocks the door when authentication is established. I have to. A plurality of portable devices are prepared for one vehicle.

  In order to detect whether the position of the portable device is in a predetermined region on the vehicle side, communication is performed between the vehicle-side device and the portable device at a predetermined time period. At this time, a request signal is transmitted from the vehicle-side device at predetermined time intervals, and when the portable device is located within a predetermined region, the request signal is received, and the received portable device has an authentication unique to each portable device. An answer signal including the information of the code is transmitted, and the vehicle side device receives it and performs authentication.

Conventionally, a door is locked when a vehicle-side device cannot receive a unique authentication code from a portable device. This means that a user with a portable device is away from the vehicle and the signal strength is high. It is assumed that the communication becomes weak and communication becomes impossible. As such a passive keyless entry device, for example, there is one as disclosed in Patent Document 1.
JP 2003-253938 A

  However, the reason why the signal from the portable device cannot be received is not limited to the case where the portable device is separated from the vehicle. This can occur, for example, when there is a communication failure between the portable device and the vehicle side device due to the presence of a shield or the like, and also when the battery of the portable device has run out. In these cases, since the door is locked, there is a possibility that unintentional locking may be performed when it should not be locked.

  The present invention has been made in view of the above problems, and provides a passive keyless entry device capable of preventing unintentional locking due to poor communication or the like when the portable device is away from the vehicle. Objective.

In order to solve the above problems, a passive keyless entry device according to the present invention transmits a request signal from a vehicle-side device provided in a vehicle at a predetermined time period, and transmits a response signal when the portable device receives the request signal. In the passive keyless entry device including a control unit that performs predetermined control when the vehicle-side device receives the answer signal or does not receive the answer signal,
The portable device includes a portable device control unit that detects the strength of a request signal transmitted from the vehicle-side device, and the portable device control unit or the control unit has a strength of the request signal that is less than or less than a predetermined value. In such a case, the portable device control unit immediately transmits a signal including information to that effect.

  In the passive keyless entry device according to the present invention, when the control unit of the vehicle side device receives a signal including information whose intensity is less than or less than a predetermined value from the portable device, the door of the vehicle is It is characterized by performing control to lock.

  According to the passive keyless entry device of the present invention, the portable device includes the portable device control unit that detects the strength of the request signal transmitted from the vehicle-side device, and the portable device control unit has a request signal strength of a predetermined value or less. When it is less than the predetermined value, it is possible to prevent unintentional locking due to poor communication or the like when the portable device moves away from the vehicle by immediately transmitting a signal including information to that effect.

  Further, according to the passive keyless entry device of the present invention, the control unit of the vehicle side device locks the door of the vehicle when receiving a signal including information whose intensity is less than or less than a predetermined value from the portable device. By performing the control, the door can be locked immediately when the portable device leaves the vehicle.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic diagram of a passive keyless entry device according to this embodiment. As shown in this figure, the passive keyless entry device according to the present embodiment includes a vehicle-side device 2 provided in a vehicle 1 having a door 1a, and a transmission antenna that is connected to the vehicle-side device 2 and arranged at various locations on the vehicle 1. 3, a receiving antenna 4 connected to the vehicle side device 2 and disposed in the vehicle 1, and a portable device 5 carried by the user. In addition, the passive keyless entry device performs wireless communication between the portable device 5 and the vehicle-side device 2 when the user approaches the vehicle 1 or leaves the vehicle 1 with the portable device 5 carried, and the door 1a. Has the function of locking and unlocking.

  In the present embodiment, the configuration and operation for locking the door 1a when the user leaves the vehicle 1 while carrying the portable device 5 will be described below. In this case, request signals are transmitted from the vehicle side device 2 at predetermined time intervals, and the portable device 5 that has received the request signal transmits a predetermined answer signal to the vehicle side device 2 that has received the answer signal. Then, predetermined control is performed based on the answer signal.

  A plurality of portable devices 5 are prepared for one vehicle 1, and each portable device 5 is provided with a unique identification code of 32 bits, for example. In the answer signal from the portable device 5, the vehicle-side device 2 authenticates the portable device 5 and identifies which portable device 5 is communicating with the signal by including an identification code unique to the portable device 5 in the signal. be able to. The answer signal from the portable device 5 including the identification code unique to each portable device 5 is hereinafter referred to as a normal response signal.

  A plurality of transmission antennas 3 are provided on the inside and the outside of the vehicle 1, respectively. When transmitting a request signal, radio waves are transmitted from all the transmission antennas 3.

  FIG. 2 shows a block diagram of the passive keyless entry device in the present embodiment. As shown in this figure, the vehicle side device 2 includes a control unit 10 that controls each unit, a memory 11 that stores an identification code and the like, a transmission unit 12 that transmits radio waves to each transmission antenna 3, and a reception antenna 4. Is provided with a receiving unit 13 that outputs the radio wave received as a signal to the control unit 10 and a lock driving unit 14 that performs locking and unlocking operations of the door 1a.

  The portable device 5 receives the request signal from the vehicle side device 2, the portable device control unit 20 that performs various controls, the portable device reception unit 21 that receives the request signal, and an answer signal to the vehicle side device 2 Mobile device transmission unit 22 and a memory 23 storing an identification code and the like. In addition, an antenna 24 that transmits and receives signals is connected to the portable device receiver 21 and the portable device transmitter 22. The portable device control unit 20 can calculate the distance from the vehicle 1 based on the intensity of the request signal received by the portable device reception unit 21.

  When receiving a normal response signal as an answer signal, the control unit 10 of the vehicle side device 2 refers to the memory 11 to authenticate the portable device 5 and based on the signal strength information received by the portable device 5. Then, it is determined whether the portable device 5 is inside or outside the boundary line that is a predetermined distance away from the vehicle 1. As a determination method, when the minimum value of the signal intensity from the plurality of antennas is equal to or less than a predetermined value or less than a predetermined value, it is determined that the signal is located outside the boundary line. Note that even when signals from three antennas are to be received and only signals from two antennas are received, the minimum value is the same as the predetermined value or less.

  Here, when the portable device control unit 20 determines that the strength is less than or less than the predetermined strength, the portable device control unit 20 can determine that the portable device 5 is outside the boundary line separated from the vehicle 1 by a predetermined distance. As a result, the answer signal is transmitted by including information indicating that it is less than or less than a predetermined strength. Information indicating whether the intensity is less than or less than the predetermined intensity is represented by 2 bits, for example, and transmitted at a predetermined position of the answer signal. When the predetermined signal is input to the control unit 10 of the vehicle side device 2, the lock driving unit 14 is controlled to lock the door 1a, and the transmission of the request signal is stopped. On the other hand, when it is determined that the portable device 5 is inside the boundary line separated from the vehicle 1 by a predetermined distance, the door 1a is not locked and the transmission of the intermittent request signal is continued. Note that the transmission of the request signal when getting off is performed when the engine is stopped and unlocked.

  The flow when the portable device 5 receives the request signal will be described in detail below. FIG. 3 shows a flowchart in the portable device 5. In this flowchart, it starts from the time (S1) when the portable device 5 receives the request signal from the vehicle side device 2. When receiving the request signal, the portable device control unit 20 detects the strength (S2).

  Subsequently, as described above, the portable device control unit 20 determines whether or not the intensity calculated in S2 is smaller than a predetermined value (S3). Here, when the strength is smaller than or less than the predetermined value, it is assumed that the portable device 5 is sufficiently separated from the vehicle 1, and a locking response signal obtained by adding information indicating this to the normal response signal is carried as an answer signal. The transmission is transmitted to the machine transmitter 22 (S4), and the flow is terminated as it is. When the vehicle-side device 2 receives a signal indicating that the strength is less than or less than a predetermined value, the control unit 10 authenticates with an identification code unique to the portable device 5 and causes the lock drive unit 14 to lock the door 1a. . Note that the signal indicating that the strength is less than or less than the predetermined value locks the door 1a as a result, and therefore may be a signal indicating a locking command.

  If the intensity is not less than the predetermined value or less than the predetermined value in S3, a signal response signal indicating that the intensity is greater than or greater than the predetermined value is returned (S5). In this case, the signal may not be returned.

  In the present embodiment, when the reception intensity of the portable device 5 is equal to or less than a predetermined value or less than the predetermined value in S3, a signal indicating this is immediately transmitted and locked. Locking can be performed immediately after a predetermined distance.

  Furthermore, the predetermined value of the strength determined in S3 is set to be shorter than the communicable distance between the portable device 5 and the vehicle-side device 2 (for example, if the communicable distance is 2.5 m, the predetermined value is 2 m. If the strength is less than or equal to the predetermined value or less than the predetermined value, a signal indicating this is immediately transmitted and the vehicle is not locked unless the signal is received. Even when the signal from 5 cannot be received, unintentional locking can be prevented.

Although the embodiment of the present invention has been described above, the application of the present invention is not limited to this embodiment, and can be variously applied within the scope of the technical idea. In this embodiment, as a determination method, when the minimum value of the signal intensity from a plurality of antennas is equal to or less than a predetermined value or less than a predetermined value, it is determined that the antenna is located outside the boundary line. It is also possible to take the average value of the intensity data from the above, or square each of the intensity data to obtain a sum, further obtain the square root of the sum, and so on. Since the intensity data decreases as the distance from the vehicle increases, in any of these cases, the portable device has detected that a distance greater than a predetermined distance from the vehicle has been detected.
In order to perform the determination more accurately, the following method can be used. That is, a large number of signal intensity information from each transmitting antenna 3 detected by the portable device 5 inside and outside the boundary line is collected in advance, a data group is created for each, and the signal actually received by the portable device 5 Whether the strength information approximates the data group inside the boundary line or the data group outside the boundary line is determined using a statistical method, and whether the portable device 5 is inside the boundary line. Determine if it is outside. As a statistical method at this time, for example, a method of calculating the Mahalanobis distance between the data from the portable device 5 and each data group and comparing which data group is approximated can be used.
Moreover, in the said Example, although the determination below or below a predetermined value is performed with a portable machine, you may transmit this data to the vehicle side and may determine on the vehicle side. In that case, when it is determined that the vehicle side is less than or less than the predetermined value, a signal indicating the result is transmitted to the portable device, and when the signal is received by the portable device, the signal indicating the predetermined value or less or less than the predetermined value. Should be sent.
Further, in the first and second embodiments, a plurality of antennas are provided. However, for example, one antenna may be provided on the door of the driver's seat or the like and the determination may be made based on the intensity data of the received signal from the antenna.

It is a schematic diagram of the passive keyless entry device in this embodiment. It is a block diagram of the passive keyless entry device in this embodiment. It is a flowchart of the portable device which received the request signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Vehicle side apparatus 5 Portable machine 10 Control part 11 Memory 20 Portable machine control part 21 Memory

Claims (2)

When a request signal is transmitted at a predetermined time period from a vehicle side device provided in the vehicle, and when the portable device receives the request signal, an answer signal is transmitted, and when the answer signal is received or not received by the vehicle side device In a passive keyless entry device equipped with a control unit for performing predetermined control,
The portable device includes a portable device control unit that detects the strength of a request signal transmitted from the vehicle-side device, and the portable device control unit or the control unit has a strength of the request signal that is less than or less than a predetermined value. In such a case, the passive keyless entry device is characterized in that a signal including information to that effect is immediately transmitted by the portable device control unit.   The control part of the said vehicle side apparatus performs control which locks the door of the said vehicle, when the signal containing the information in which the said intensity | strength is less than predetermined value or less than predetermined value is received from the said portable device. The passive keyless entry device according to 1.

Images