JP4812819B2 - Keyless entry device - Google Patents

Description

  The present invention relates to a keyless entry device that locks and unlocks a door of a vehicle by performing wireless communication between the vehicle-side device and the portable device, and in particular, the distance between the transmission antenna of the vehicle-side device and the portable device is a signal strength. The present invention relates to a keyless entry device that is calculated by detection.

  2. Description of the Related Art Conventionally, a keyless entry device that performs wireless communication between a vehicle-side device provided in a vehicle and a portable device carried by a user to lock and unlock a vehicle door is known. In recent years, when a portable device approaches the vehicle, communication is automatically performed between the vehicle-side device and the portable device, and if the ID that is uniquely set for each portable device is authenticated, A passive keyless entry device that performs locking and unlocking operations is also known.

By the way, in the passive keyless entry device, it is important to be able to determine whether the portable device is outside or inside the vehicle. For this purpose, the vehicle-side device is provided with a plurality of transmission antennas at various locations of the vehicle, detects the signal strength received by the portable device for each transmission antenna, and determines the transmission antenna and portable device from this signal strength. The distance was calculated and the position of the portable device was measured. As described above, for example, Patent Document 1 discloses a technique for measuring the position of a wireless terminal device such as a portable device based on the signal strength received from a plurality of transmission antennas.
Japanese Patent Laid-Open No. 5-11039

  When the position measurement technique based on the received signal strength is used for the keyless entry device, there are the following problems. Since the power source provided in the vehicle is a battery, the output varies depending on the degree of charge. For this reason, the output level of the signal transmitted from the transmission antenna has fluctuated. In order to accurately measure the position of the portable device, the output level of the signal transmitted from the transmission antenna needs to be constant with high accuracy. For this reason, a regulator may be provided. Was difficult. Therefore, the position of the portable device could not be measured with sufficient accuracy.

  The present invention has been made in view of the above problems, and provides a keyless entry device that can accurately measure the position of a portable device based on the received signal strength even if the power output of the vehicle fluctuates. Objective.

In order to solve the above-described problem, a keyless entry device according to the present invention includes a vehicle-side transmission unit that is provided in a vehicle and is connected to a plurality of transmission antennas that transmit request signals, and a vehicle-side reception unit that receives an answer signal. In a keyless entry device having a vehicle-side device, a portable device reception unit that receives the request signal, and a portable device that includes a portable device transmission unit that transmits an answer signal,
The vehicle-side device authenticates an answer signal from the portable device and supplies power from a vehicle-side control unit that performs predetermined control and a power supply unit of the vehicle to the transmission antenna. a drive circuit provided on the vehicle side transmission section for driving to transmit a signal, when the drive circuit is to transmit a signal to the transmitting antenna, a power measuring circuit for measuring the output level of the signal, the output measurement A memory for storing an output level measured by a circuit, wherein the portable device includes a portable device control unit that detects each intensity of a signal transmitted from a plurality of transmission antennas of the vehicle side device; Send a signal according to the intensity,
The vehicle-side control unit includes the transmission antenna and the mobile phone based on intensity data detected by the portable device control unit based on output level data of a signal in the drive circuit measured by the output measurement circuit stored in the memory. The distance data between the devices is corrected, and the distance between each transmitting antenna and the portable device is calculated.

  In the keyless entry device according to the present invention, the drive circuit includes an amplifier unit that amplifies a signal to be transmitted to the transmission antenna, and the output measurement circuit measures an output level from the amplifier unit. Has been.

  Furthermore, in the keyless entry device according to the present invention, the portable device control unit calculates a distance from the transmission antenna that transmitted the signal based on the detected signal strength, and transmits the distance data included in the answer signal. It is configured as a feature.

  Furthermore, the keyless entry device according to the present invention is characterized in that each of the plurality of transmission antennas is connected to one drive circuit, and the output measurement circuit is connected to the drive circuit.

  In the keyless entry device according to the present invention, the vehicle-side control unit includes a storage unit that stores in advance a unique characteristic of each transmission antenna, and calculates an actual distance between each transmission antenna and the portable device. In addition, characteristic data stored in the storage unit is also used.

  In the keyless entry device according to the present invention, the output level data stored in the memory is transmitted or transmitted when the portable device control unit receives a signal received to obtain distance data between each transmission antenna and the portable device. The data is configured immediately before or immediately after transmission.

  According to the keyless entry device according to the present invention, the vehicle-side device supplies power from the power supply unit of the vehicle to the transmission antenna and drives to transmit a signal from the vehicle-side control unit, and the drive An output measurement circuit that measures an output level of a signal that the circuit transmits to the transmission antenna, and the vehicle-side control unit includes distance data between each transmission antenna and the portable device based on intensity data detected by the portable device control unit; Even if the power output of the vehicle fluctuates, the signal strength is measured by calculating the actual distance between each transmitting antenna and the portable device from the output level data of the signal in the drive circuit measured by the output measuring circuit. Accordingly, the accuracy of the distance measurement between the portable device and the transmitting antenna can be increased, so that the accuracy of position determination of the portable device can be increased. Further, the output level of the signal transmitted from the transmission antenna of the vehicle does not need to be transmitted to the outside as a transmission signal, and the measurement of the distance with improved accuracy is completed on the vehicle side and is simple.

  According to the keyless entry device of the present invention, the drive circuit includes an amplifier unit that amplifies a signal to be transmitted to the transmission antenna, and the output measurement circuit transmits the signal from the transmission antenna by measuring the output level from the amplifier unit. Since the intensity of the transmitted signal can be measured more directly, the accuracy can be further improved.

  Furthermore, according to the keyless entry device according to the present invention, the portable device control unit calculates the distance from the transmission antenna that transmitted the signal based on the detected signal strength, and transmits the distance data in the answer signal. As a result, the signal strength data is composed of numerical data in three axes, whereas the distance data is composed of a single numerical data, so that the amount of data transmitted from the portable device to the vehicle-side control unit can be reduced. .

  Furthermore, according to the keyless entry device of the present invention, each of the plurality of transmission antennas is connected to one drive circuit, and the output measurement circuit is connected to the drive circuit, thereby driving each transmission antenna. There is no need to provide a circuit or an output measurement circuit, and the cost can be reduced by simplifying the circuit.

  According to the keyless entry device of the present invention, the vehicle-side control unit includes a storage unit that stores in advance the unique characteristics of each transmission antenna, and calculates the actual distance between each transmission antenna and the portable device. By using the characteristic data stored in the storage unit, it is possible to further improve the accuracy in consideration of variation in characteristics for each transmission antenna.

  In addition, according to the keyless entry device according to the present invention, the value when the portable device transmits a signal for calculating the distance from the antenna, or a value that can be regarded as the same with only a short time lag. Since is used, the accuracy is further improved.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic diagram of a keyless entry device according to this embodiment. The keyless entry device according to the present embodiment locks or unlocks the door 1a of the vehicle 1. The vehicle-side device 2 is provided on the vehicle 1, the user carries the portable device 3, and the vehicle-side device. Wireless communication is performed between the mobile phone 3 and the portable device 3 to perform authentication, locking / unlocking commands, and the like. In the present embodiment, one vehicle can be locked or unlocked by a predetermined plurality of portable devices. The vehicle-side device 2 has a plurality of transmission antennas 15 at various locations of the vehicle 1, and a request signal is transmitted from each transmission antenna 15 to the portable device 3. The request signal is a low frequency signal.

  Hereinafter, a case where the user approaches the vehicle 1 and unlocks the door 1a will be mainly described. In the present embodiment, in order to unlock the door 1a, the user having the portable device 3 needs to press the request switch 16 provided near the door knob 1b of the door 1a. When the request switch 16 is pressed, communication such as authentication is performed between the vehicle-side device 2 and the portable device 3, and when the authentication is made, the vehicle-side device 2 unlocks the door 1a.

  Next, the structure of the vehicle side apparatus 2 and the portable device 3 is demonstrated. FIG. 2 shows a block diagram of the keyless entry device. As shown in this figure, the vehicle-side device 2 includes a vehicle-side receiver 10 that receives an answer signal from the portable device 3, a vehicle-side transmitter 11 that transmits a request signal to the portable device 3, and an answer signal. And a vehicle-side control unit 12 that performs various controls when the request switch 16 is pressed.

  In addition, the vehicle-side control unit 12 includes a V-ID (Vhicle-ID) composed of binary data having a small number of bits and an identification code unique to the vehicle, and a plurality of portable devices that can operate one vehicle. The above-described request switch 16 is connected to a memory 13 that stores information necessary for control such as each ID and output characteristics unique to each transmission antenna 15. Furthermore, a receiving antenna 14 for receiving an answer signal is connected to the vehicle-side receiving unit 10, and a plurality of transmitting antennas 15 and 15 for transmitting a request signal are connected to the vehicle-side transmitting unit 11. The plurality of transmission antennas 15 and 15 are provided at various locations inside and outside the vehicle 1, respectively.

  The vehicle-side transmission unit 11 is provided with a drive circuit 17 that drives each transmission antenna 15. The drive circuit 17 is connected to all the transmission antennas 15 and supplies power to each transmission antenna 15 so that a signal from the vehicle-side control unit 12 is transmitted from the transmission antenna 15. Therefore, the drive circuit 17 is connected to the power supply unit 4 provided in the vehicle 1 and includes an amplifier unit 17 a that amplifies a signal from the vehicle-side control unit 12.

  Since the power supply unit 4 of the vehicle 1 is composed of a battery, the output varies depending on the status of other loads driven by a battery such as an audio or air conditioner, the charging status, and the like. Therefore, an output measurement circuit 18 that measures the output level of the signal output from the amplifier unit 17a is connected to the drive circuit 17. The output measuring circuit 18 transmits the output level of the measured signal to the vehicle-side control unit 12 and stores it in the memory 13. Based on the output level data stored in the memory 13 and the data received from the portable device 3, the vehicle-side control unit 12 calculates the distance between each transmission antenna 15 and the portable device 3 with high accuracy.

  The portable device 3 includes a portable device receiver 20 that receives a request signal from the vehicle-side device 2, a portable device transmitter 21 that transmits an answer signal to the vehicle-side device 2, and various types of signals when receiving a request signal. It has the portable device control part 22 which performs control, and the memory 24 which memorize | stored ID, V-ID, etc. which were set to the own machine. In addition, the portable device receiving unit 20 and the portable device transmitting unit 21 are connected to a three-axis antenna 23 that transmits and receives request signals and answer signals and has directivity characteristics in directions orthogonal to each other.

  The portable device control unit 22 switches from the sleep state in which the power consumption is substantially zero to the normal state by the wakeup signal included in the request signal from the vehicle side device 2 received by the portable device reception unit 20. In addition, the portable device control unit 22 performs various operations based on commands included in the request signal. Furthermore, the portable device control unit 22 can detect the strength of the signal received by the triaxial antenna 23 and calculate the distance between the transmission antenna 15 that has transmitted the signal and the portable device 3 based on the strength data. .

  Next, the operation of the keyless entry device will be described. In FIG. 3, the flowchart about the operation | movement at the time of unlocking a door is shown. FIG. 4 shows a chart of signals transmitted from the vehicle-side device 2 and the portable device 3 in the flow of FIG. The keyless entry device of the present embodiment is such that when a request switch 16 provided in the vehicle 1 is pressed, wireless communication is performed between the vehicle side device 2 and the portable device 3 and the door is unlocked. is there. Therefore, the flow starts when the user first presses the request switch 16 of the vehicle 1 (S1).

  When the request switch 16 is pressed, first, in S1 to S7, it is determined whether or not there is a portable device around the vehicle and if there is a plurality of portable devices. Specifically, the vehicle side control unit 12 outputs a control signal to the vehicle side transmission unit 11 to transmit the request signal LF1 from one transmission antenna 15 (S2). As shown in FIG. 7, the request signal LF1 includes a signal A including a wakeup signal and a command signal CMD. The command signal CMD includes V-ID (Vhicle-ID) information, which is a vehicle-specific identification code.

  When the portable device 3 receives the request signal LF1 at the portable device receiver 20 (S3), the portable device controller 22 changes from the sleep state to the normal state by the wake-up signal, and the V-ID included in the request signal LF1 is It is determined whether or not it matches the V-ID held (S4). If the V-IDs do not match, the flow ends there. If the V-IDs match, the portable device control unit 22 causes the portable device transmission unit 21 to transmit the answer signal RF1 including the V-ID (S5). In the plurality of portable devices 3, after receiving the signal, RF1 is transmitted after a predetermined time set in advance in each portable device.

  The vehicle-side control unit 12 determines whether or not the vehicle-side receiving unit 10 has received an answer signal RF1 including a predetermined V-ID within a predetermined time after transmitting LF1 by the transmission antenna 15 (S6). ). Here, the predetermined time is a time obtained by adding some margin to the maximum time set for the plurality of portable devices 3, and the answer signal RF1 is not returned within the predetermined time. In this case, it is considered that none of the predetermined operable portable devices 3 could be detected. If it is determined in S6 that no signal has been received, the transmitting antenna 15 that transmits the LF1 signal is changed (S7), and the same operation is performed. If it is determined that the signal has been received in S6, the mobile device 3 is identified from the transmission time of LF1 and the reception time of RF1. In addition, the LF1 to which the RF1 is returned also identifies which transmission antenna 15 is used for transmission. Since V-ID is composed of binary data of several bits, the communication time can be short.

  Next, in S8 and after, the mobile device is strictly authenticated and the distance is measured. Specifically, the vehicle-side control unit 12 first transmits a second request signal to the vehicle-side transmission unit 11 (S9). As shown in FIG. 4, the second request signal LF2 is transmitted from the transmission antenna 15 that has transmitted the LF1 to which the RF1 is returned, and includes the wake-up signal as with the request signal LF1, and the predetermined mobile phone specified above. It consists of a signal B including the ID of the machine 3, a signal including the command signal CMD, and a plurality of Rssi measurement signals transmitted in order from each transmission antenna 15.

  The Rssi measurement signal transmitted from each transmission antenna 15 is a pulse-shaped signal having a predetermined intensity and continuing for a predetermined time as shown in FIG. 4, and is used for measuring the reception intensity on the portable device 3 side. Used for. Each Rssi measurement signal is transmitted by the vehicle-side transmitter 11 from each transmitting antenna 15 in a predetermined order and at a predetermined time interval after a predetermined time has elapsed after receiving the RF1 signal from the portable device. The portable device 3 stores information on which signal from which transmitting antenna 15 is transmitted at which timing from the reception of the RF1 signal on the vehicle side, and starts a timer from the time when the RF1 signal is received. And measure the reception time. Then, by comparing the two, it is possible to identify from which transmitting antenna 15 the Rssi measurement signal is transmitted.

  When transmitting the second request signal LF2 in S9, the output measurement circuit 18 provided in the vehicle side device 2 measures the output level of the signal output from the amplifier unit 17a of the drive circuit 17, and outputs the output level data. It transmits to the vehicle side control part 12. The vehicle-side controller 12 temporarily stores the output level data in the memory 13 (S8). Actually, it takes a time of several msec to measure at the time C in FIG. 4 and to transmit signals from all the transmitting antennas 15.

  The second request signal LF2 transmitted from each transmission antenna 15 is received by the portable device receiver 20 of the portable device 3 (S10). The portable device control unit 22 measures the intensity of each Rssi measurement signal with the triaxial antenna 23 as described above, and determines the intensity of each transmission antenna 15 from the intensity data for each transmission antenna 15 obtained from the triaxial antenna 23. The distance data information obtained by calculating the distance to the portable device 3, that is, in this example, three data respectively indicating the distances between the three transmission antennas 15 and the portable device 3 are used as the second answer signal RF 2 to the vehicle side device 2. Transmit (S11). At this time, the answer signal RF2 is also transmitted including a HU-ID (Hand Unit-ID) which is an ID uniquely set for each portable device. Note that the signal strength measurement is not limited to transmitting the Rssi measurement signal from the vehicle 1 side and measuring the strength on the portable device 3 side, and omitting the transmission of the Rssi signal, The signal B including the ID of the portable device of the second request signal or the command signal CMD may be transmitted from each of the plurality of transmission antennas 15 and its own signal strength may be measured.

  The vehicle-side transmitter 11 of the vehicle-side device 2 receives the answer signal RF2 from the portable device 3 (S12). When the answer signal RF2 is received, the vehicle-side control unit 12 determines whether or not the HU-ID included therein matches the one registered in the vehicle (S13). Here, if the HU-ID does not match that registered in the vehicle, the flow ends there. On the other hand, if the HU-ID matches that registered in the vehicle, then the distance between the portable device 3 and the transmission antenna 15 is detected (S13).

  As described above, at the time of transmission / reception of the request signal LF1, after transmitting the request signal LF1, the answer signal RF1 is transmitted after a different time for each portable device 3, and a plurality of portable devices are measured by measuring this time. The portable device 3 is specified quickly and easily depending on which one of the three has a response. At the time of transmission / reception of the second request signal LF2, first, accurate authentication using the individual ID (HU-ID) of the portable device having a larger amount of information with respect to the portable device 3 detected in the request signal LF1, and each transmitting antenna 15 Measure the distance to. The details are omitted in the above description, but if the authentication cannot be performed, the same operation is performed on each portable device 3. The identification of the portable device 3 in the request signal LF1 is omitted, and only the authentication using the individual ID (HU-ID) of each portable device 3 is performed, or the individual using the individual ID (HU-ID) is performed. The authentication of the portable device 3 can be performed after the transmission of the Rssi measurement signal.

  The position of the portable device 3 is detected along the following flow. FIG. 5 shows a flowchart for determining the position of the portable device 3. FIG. 6 is a schematic plan view of the vehicle 1 and shows a position where the transmission antenna 15 is installed. First, the vehicle-side control unit 12 extracts identification information included in the answer signal RF2 transmitted from the portable device 3 and distance data between each transmission antenna 15 and the portable device 3 (S14-1).

  Moreover, the vehicle side control part 12 reads the output data measured by the output measurement circuit 18 at the time of signal transmission and the characteristic value of each transmission antenna 15 from the memory 13 (S14-2). These data are used to set the distance data to each transmission antenna 15 calculated from the intensity of the Rssi measurement signal received by the portable device 3 as the actual distance. Here, the distance data calculated by the portable device 3 is calculated from the strength of the Rssi signal on the assumption that a radio wave having a reference strength is output from the transmission antenna 15.

  Subsequently, the vehicle-side controller 12 applies the characteristic value and output data of the transmission antenna 15 to the distance data calculated by the portable device 3, and calculates a highly accurate distance (S14-3). That is, as described above, the portable device 3 calculates the distance on the assumption that the radio wave having the reference intensity is output from the transmission antenna 15, but actually supplies the radio wave to the amplifier 17a of the transmission unit according to fluctuations in the power supply voltage and the like. The output power fluctuates, and even if the predetermined power is supplied due to variations in the characteristics of the transmitting antenna 15, a signal with a predetermined electric field strength may not be output. To do.

  The aforementioned characteristic values stored in the memory 13 are set for each transmission antenna 15 and are measured in advance when the vehicle 1 is manufactured. Specifically, when the output of the reference value is applied to the transmission antenna 15, the intensity of the radio wave actually output from the transmission antenna 15 is measured for each transmission antenna 15. By obtaining the value based on the actual distance value calculated for each transmission antenna 15 calculated by the portable device 3 and the characteristic value for each transmission antenna 15, the influence of the inherent variation for each transmission antenna 15 can be reduced. . Since the distance is proportional to 1 / (the third power of the signal strength), a value obtained by dividing the strength of the radio wave measured at the time of manufacture by the reference strength is raised to the third power, and the reciprocal number is multiplied by the measured value of the distance, or By correcting with the conversion table, a highly accurate distance in which the influence of the characteristic value of the transmission antenna 15 is reduced is obtained.

  The output data measured by the output measurement circuit 18 is a voltage value or a current value of power supplied from the power supply unit 4. For this reason, the vehicle-side controller 12 can calculate the distance with high accuracy by multiplying the ratio of the output data to the rated value by the ratio of the distance, that is, the reciprocal of the cube of the ratio in the same manner as described above, to the actually measured value. it can. The calculation of the distance with high accuracy here is not only based on the calculated value as described above, but a multiplier corresponding to each range of the output data is experimentally obtained and set, and it is multiplied by the actually measured value. Alternatively, a multiplier function using output data as a parameter may be set, and a multiplier may be calculated based on the multiplier function and multiplied by an actual measurement value. In the above, after obtaining the distance so that the influence of the characteristic value of the transmission antenna 15 is reduced, the distance is obtained so as to reduce the influence of the output value with respect to the distance, but in the reverse order. It may be performed, or a distance with high accuracy may be obtained in consideration of both at the same time. Further, if the characteristic value of the transmission antenna 15 is negligible, the distance may be obtained without considering this.

  As described above, the output measurement circuit 18 is provided in the vehicle-side device 2, the output level of the signal transmitted by the drive circuit 17 to the transmission antenna 15 is measured, and the output level data and the intensity data of the signal detected by the portable device 3. Even if the power output of the vehicle 1 fluctuates, the portable device 3 and the transmission antenna 15 can be obtained by measuring the signal strength even if the power output of the vehicle 1 fluctuates. Therefore, the accuracy of position determination of the portable device 3 can be increased. Further, since the output level is measured by the output value from the amplifier unit 17a of the drive circuit 17, for example, the intensity of the signal transmitted from the transmission antenna 15 is directly compared with the case where the voltage of the power supply unit 4 is measured. Can be measured automatically, and the accuracy can be further improved.

  When the distance between the portable device 3 and each transmitting antenna 15 is calculated, the position of the portable device 3 is determined from this distance data (S14-4). As shown in FIG. 6, the vehicle 1 is provided with transmission antennas 15 at three locations, and the distance between each transmission antenna 15 and the portable device 3 is obtained. In FIG. 6, reference numerals 15a, 15b, and 15c are assigned to the three transmission antennas, respectively. The distance between the transmission antenna 15a and the portable device 3 is L1, the distance between the transmission antenna 15b and the portable device 3 is L2, and the transmission antenna. The distance between 15c and the portable device 3 is L3.

  C1 shown in FIG. 6 is an arc having a radius L1 centered on the position of the transmitting antenna 15a, C2 is an arc having a radius L2 centered on the position of the transmitting antenna 15b, and C3 is a position of the transmitting antenna 15c. Is a circular arc with a radius L3. These arcs are actually a part of a spherical surface, but in FIG. 6, they are simplified and represented as a plan view at a predetermined height. The position at which these arcs intersect at one point is the position of the portable device 3, and whether the portable device 3 is located inside the vehicle or outside the vehicle depending on whether this is the inside or outside region of the vehicle 1. Determine.

  Thereafter, the vehicle-side control unit 12 performs different control depending on whether the portable device 3 is inside the vehicle 1 or outside the vehicle 1 (S15). When it is determined that the position of the portable device 3 is not outside the vehicle 1, that is, the portable device 3 is inside the vehicle 1, the flow is finished as it is.

  When the door is unlocked by pressing the request switch 16, the portable device 3 should be outside the vehicle 1. When the portable device 3 is inside the vehicle 1 together with the user, Even a person who does not have the machine 3 can press the request switch 16 to unlock the door. In order to prevent this, when the portable device 3 is in the vehicle 1, the door is not unlocked. On the other hand, when it is determined that the position of the portable device 3 is outside the vehicle 1, an unlock command signal is output to the door locking device (not shown), and the door is unlocked (S16).

  Although the operation of unlocking the door by pressing the request switch 16 is shown here, the position determination of the portable device 3 can be similarly performed for the operation of locking the door, and control according to the result can be performed. Further, not only the door locking / unlocking operation, but also the operation of starting the engine according to the position of the portable device 3, the position of the portable device 3 is similarly determined, and the operation is performed according to the result. be able to.

  As mentioned above, although embodiment of this invention was described, application of this invention is not restricted to these embodiment, It can apply variously within the range of the technical idea. For example, in this embodiment, the vehicle-side control unit 12 controls transmission of the output value of the output measurement circuit 18 to the memory 13 and transmission of the signal of the transmission antenna 15, so that the output of the output measurement circuit 18 is output. The transmission output is measured at a time different from the measurement of the value, but if the memory is provided in the output measurement circuit 18 to store the data, or the vehicle-side control unit 12 is capable of performing a plurality of processes simultaneously, the transmission is transmitted. The output voltage can be measured. However, there is no problem because the output voltage hardly changes if it is just before or immediately after transmission, specifically, 1 second or less.

  In this embodiment, since the output value is measured when the second request signal LF2 is transmitted, the signal used for measuring the distance between the portable device 3 and the transmission antenna 15 is transmitted and the output measurement time is Although the difference can be reduced, the measurement of the distance at the portable device 3 in the second request signal LF2 is the same, and the output value is measured by the output measurement circuit 18 at the time of transmission of the request signal LF1, and this measured output value and this reference output It may be obtained from the value. That is, in this type of keyless entry device, the time from when the request switch 16 is pressed until the door is unlocked is set short, and in this case, the time interval is also short.

  In this embodiment, the output measurement circuit 18 measures the output value once before transmitting signals from the three transmitting antennas 15. However, before transmitting signals from each transmitting antenna 15, the output value is measured each time. For each transmission antenna 15, the distance between the transmission antenna 15 and the portable device 3 transmitted from the portable device 3 is obtained again, or measured at an intermediate time of signal transmission and transmitted from the preceding and subsequent transmission antennas 15. The output value of the signal can be used.

  In the present embodiment, the distance data between the portable device 3 and each transmission antenna 15 is transmitted from the portable device 3, but this is not limited to the distance itself, and any data corresponding to the distance may be used. good. Further, in the present embodiment, the distance between the portable device 3 and the transmission antenna 15 is calculated based on the signal strength data on the portable device 3 side, and the distance data is transmitted to the vehicle side device 2. The intensity data of each of the triaxial antennas 23 is transmitted from the portable device 3 for each transmission antenna 15, the distance between each transmission antenna 15 and the portable device 3 is calculated in the vehicle side device 2, and the output value of the output measurement circuit 18 The distance may be obtained with high accuracy again. In this case, the vehicle-side device 2 may obtain again the intensity data of each of the three-axis antennas 23 based on the output value of the output measurement circuit 18 and obtain the distance from that value. That is, the data transmitted from the portable device 3 may be data corresponding to the strength, and the distance may be obtained by the portable device 3 or by the vehicle 1 side. However, when transmitting the intensity data of each of the triaxial antennas 23, the amount of data transmitted from the portable device 3 increases. When transmitting by distance data, since there is only one data for one transmission antenna 15, the amount of data transmitted from the portable device 3 to the vehicle side device 2 can be reduced by configuring as in the present embodiment. can do.

It is a schematic diagram of the keyless entry device in this embodiment. It is a block diagram of a keyless entry device. It is a flowchart in the case of unlocking operation | movement. It is a chart figure of the signal from a vehicle side apparatus and a portable machine. It is a flowchart of position determination of a portable machine. FIG. 3 is a schematic plan view of a vehicle and shows a setting position of a transmission antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Vehicle side apparatus 3 Portable machine 4 Power supply part 10 Vehicle side receiving part 11 Vehicle side transmission part 12 Vehicle side control part 13 Memory 14 Reception antenna 15 Transmission antenna 16 Request switch 20 Portable machine receiving part 21 Portable machine transmission part 22 Carrying Machine control unit 23 Triaxial antenna

Claims (6)

A vehicle-side device provided with a vehicle-side transmitter connected to a plurality of transmission antennas provided in a vehicle and transmitting a request signal, a vehicle-side receiver that receives an answer signal, and a portable device receiver that receives the request signal In a keyless entry device having a portable device including a portable device and a portable device transmitter for transmitting an answer signal,
The vehicle-side device authenticates an answer signal from the portable device and supplies power from a vehicle-side control unit that performs predetermined control and a power supply unit of the vehicle to the transmission antenna. a drive circuit provided on the vehicle side transmission section for driving to transmit a signal, when the drive circuit is to transmit a signal to the transmitting antenna, a power measuring circuit for measuring the output level of the signal, the output measurement A memory for storing an output level measured by a circuit, wherein the portable device includes a portable device control unit that detects each intensity of a signal transmitted from a plurality of transmission antennas of the vehicle side device; Send a signal according to the intensity,
The vehicle-side control unit includes the transmission antenna and the mobile phone based on intensity data detected by the portable device control unit based on output level data of a signal in the drive circuit measured by the output measurement circuit stored in the memory. A keyless entry device that corrects distance data between devices and calculates a distance between each transmitting antenna and a portable device.   2. The keyless entry device according to claim 1, wherein the drive circuit includes an amplifier unit that amplifies a signal to be transmitted to the transmission antenna, and the output measurement circuit measures an output level from the amplifier unit.   3. The portable device control unit calculates a distance from a transmission antenna that has transmitted the signal based on the detected signal strength, and transmits the distance data included in the answer signal. The keyless entry device described.   4. The keyless entry device according to claim 1, wherein each of the plurality of transmission antennas is connected to one drive circuit, and the output measurement circuit is connected to the drive circuit. 5. .   The vehicle-side control unit includes a storage unit that stores in advance a unique characteristic for each transmission antenna, and characteristic data stored in the storage unit when calculating an actual distance between each transmission antenna and the portable device is also included. The keyless entry device according to any one of claims 1 to 4, wherein the keyless entry device is used.   The output level data stored in the memory is data when the portable device control unit transmits a signal received in order to obtain distance data between each transmission antenna and the portable device, immediately before transmission, or immediately after transmission. The keyless entry device according to claim 1.

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