JP2009278597A - Multi-channel communication system and electronic key system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-channel communication system whose electric power consumption required for wireless communication is reduced and wireless communication is carried out in a short time. <P>SOLUTION: The multi-channel communication system is equipped with an electronic key which can transmit radio waves through a plurality of channels CH1, CH2 and an in-vehicle communication control device which can receive radio waves transmitted from the electronic key by a polling operation in a predetermined period. After the electronic key continuously transmits a plurality of CH1 frames 101, ... including each bit data through CH1, the electronic key continuously transmits a plurality of CH2 frames including each bit data through CH2 at a frequency different from that of CH1 so as to carry out wireless communication even under a circumference of noise disturbing the reception of CH1 radio wave. A dummy bit 102f of a time length α is added to the bit data contained in each CH2 frame 102, ... to extend a frame length (ΔTf+α)[sec] of the CH2 frame. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multi-channel communication system that performs wireless communication using radio waves in a plurality of frequency bands, and an electronic key system using the same.

  In recent years, wireless communication is performed between an electronic key possessed by a user of a vehicle and an in-vehicle communication control device mounted on the vehicle, and the door control of the vehicle is performed through verification of an ID code transmitted by the wireless communication. Electronic key systems have been developed that permit or execute lock operations and engine start / stop operations.

  In this electronic key system, the electronic key is provided with an operation switch for controlling various in-vehicle devices. For example, when the lock switch is operated, an ID code and a lock request signal are wirelessly transmitted from the electronic key. When the ID code can be verified, the door of the vehicle is locked. On the other hand, when the unlocking switch is operated with the electronic key, the ID code and the unlocking request signal are wirelessly transmitted from the electronic key, and the vehicle door is unlocked when the ID code can be verified.

  As described above, when the electronic key system is provided in the vehicle, when performing the locking / unlocking operation of the door of the vehicle, the troublesome mechanical operation of inserting and turning the mechanical key into the key cylinder is not required, and the door opening / closing is not required. The lock operation can be performed remotely and automatically.

  In recent years, various wireless communication devices have been developed, and wireless communication is used for exchanging various data. This radio wave includes so-called “environmental noise” which exists around the vehicle and interferes with wireless communication performed between the vehicle and the electronic key.

  Therefore, in such an electronic key system, as shown in FIG. 4, a data signal Swkb is used as a signal used to control various in-vehicle devices mounted on the vehicle, and the electronic key is directed from the electronic key toward the vehicle. In one channel (hereinafter referred to as “CH1”), three (a plurality of) frames 201 (hereinafter referred to as “CH1 frame 201”) are transmitted in succession, each including bit data (bit information). Later, each of the four (plural) frames 202 (hereinafter referred to as “CH2 frame 202”) in a second channel (hereinafter referred to as “CH2”) belonging to the UHF band and having a frequency different from that of the first channel. A multi-channel communication system including bit data and continuously transmitting is being adopted (see, for example, Patent Document 1).

  As shown in FIG. 4, the data signal Swkb has a data format in which CH1 and CH2 frames 201,..., 202,. . 7 (plural) CH1 frames 201,..., CH2 frames 202,... Are transmitted by the vehicle because of the presence of an electronic key having a similar transmission frequency and the influence of environmental noise. Since it is assumed that the CH1 or CH2 frame 201 or 202 is received from the middle through the reception of any one of the CH1 or CH2 frames 201 or 202 in a complete state, the bit data included in the CH1 or CH2 frame 201 or 202 is received. This is for receiving the whole.

  Specifically, as shown in FIG. 4, each frame 201 (202) includes a start bit 201a (202a) for notifying the vehicle-mounted communication control device of the start of data transmission, and a code unique to each electronic key. ID code 201b (202b), rolling code 201c (202c) that changes every time a lock switch or unlock switch is operated, a lock request signal Slk for unlocking the door, or unlocking the door A function code 201d (202d) as specific instruction contents of the unlock request signal Sul for enabling the state and a stop bit 201e (202e) for distinguishing from the next start bit are used as bit data. Included in one piece. The stop bit 201e (202e) is also necessary for the in-vehicle communication control device to obtain data processing time.

  Then, the in-vehicle communication control device receives any one of the CH1 and CH2 frames 201,..., 202,... In a complete state from the start bit 201a (202a) to the stop bit 201e (202e) at the end. The lock request signal Slk or the unlock request signal Sul is received by the in-vehicle communication control device, and the reception of the data signal Swkb is completed. That is, in this way, in the electronic key system, wireless communication is established between the electronic key and the in-vehicle communication control device.

  An operation example of an electronic key system as this type of multi-channel communication system will be described with reference to FIGS. 5 to 8. As shown in FIG. 5, when a lock switch or an unlock switch is operated on the electronic key. The electronic key transmits a data signal Swkb including a command content corresponding to the switch operation from the transmission circuit.

  Further, when the electronic key wirelessly transmits to the vehicle a data signal Swkb composed of a total of seven CH1 and CH2 frames 201,..., 202,. It modulates and transmits to the radio wave of frequency (CH1, CH2). Here, the frame length (frame time length) of each frame 201 (202) is assumed to be ΔTf [sec].

  In the example shown in FIG. 5, the electronic key first wirelessly transmits bit data of three (plural) CH1 frames 201,... At CH1 frequency in time series, and then at 4 CH2 frequency. Bit data of one (plurality) of CH2 frames 202,. That is, in the electronic key, when the lock switch or the unlock switch is operated, the data signal Swkb including three CH1 frames 201,..., Followed by four CH2 frames 202,. Is sent to the vehicle.

  On the other hand, in FIG. 5, the in-vehicle communication control device performs a polling operation 50 for checking whether or not control radio waves (radio waves transmitted by CH1 and CH2) are transmitted from the electronic key via the in-vehicle communication device. It is performed with a short time period (polling period ΔTp [sec]) of about 300 msec. In each polling operation 50, first, a CH1 reception preparation operation 51 for preparing CH1 bit data reception is performed for a predetermined time, and then a CH2 reception preparation operation 52 for preparing CH2 bit data reception is performed for a predetermined time. ing. The CH1 reception preparation operation 51 and the CH2 reception preparation operation 52 mean operations for tuning the reception frequency to the transmission frequencies assigned to CH1 and CH2, respectively, in the in-vehicle communication control device.

  Here, as shown in FIG. 5, for example, assuming that there is no environmental noise around the vehicle that interferes with reception of the CH1 frame 201, in this state, the CH1 frame 201 is transferred to the in-vehicle communication control device. It is transmitted normally. For this reason, the in-vehicle communication control device confirms the reception of the CH1 frame 201 in the CH1 reception preparation operation 51 by the start bit search operation 51a for searching for the start bit, and then the bit data included in the CH1 frame 201 is checked. The whole is acquired during the frame length ΔTf by the CH1 data receiving operation 51b, and the reception of the data signal Swkb from the electronic key is completed.

  On the other hand, as shown in FIG. 6, assuming that there is an environmental noise around the vehicle that interferes with the reception of the CH1 frame 201, in this state, the reception of the CH1 frame 201 belongs to the CH1 frequency band. The noise is completely disturbed by random noise 41r (disturbed noise whose frequency and intensity are not constant), and none of the CH1 frames 201,... Is transmitted normally to the in-vehicle communication control device at all three transmission timings. For this reason, the in-vehicle communication control device cannot receive each CH1 frame 201,... At all during the CH1 reception preparation operation 51,... In the polling operation 50,. Then, during the CH2 reception preparation operation 52 in the first polling operation 50 after shifting to the transmission timing of the CH2 frame 202, the reception of the CH2 frame 202 is confirmed by the start bit search operation 52a for searching for the start bit, and thereafter The entire bit data included in the CH2 frame 202 is acquired during the frame length ΔTf by the CH2 data receiving operation 52b, and the reception of the data signal Swkb from the electronic key is completed.

According to this technique, as shown in FIG. 6, when the data signal Swkb from the electronic key is received in the middle of the CH2 frame 202 by the in-vehicle communication control device, the CH2 frame 202 following the CH2 frame 202 is received. A start bit search operation 52a for searching for a start bit is performed, and bit data included in the CH2 frame 202 is acquired as received data.
JP 2007-142886 A

  By the way, under this technique, as shown in FIG. 7, there are random noises 41r, which are environmental noises belonging to the frequency band of CH1, at the transmission timing of the CH1 frame 201 that is three times in total, and a total of 4 It is assumed that there is a format noise 41f (frequency transmitted from the same kind of electronic key, regular noise with constant intensity), which is environmental noise belonging to the frequency band of CH1, at the transmission timing of a certain CH2 frame 202. Note that the state shown in FIG. 7 assumes a worst state in which wireless communication performed in an electronic key system including an electronic key and an in-vehicle communication control device is almost completely disturbed by environmental noise.

  In this state, similarly to the state shown in FIG. 6, the in-vehicle communication control device is disturbed by the random noise 41r, and during the CH1 reception preparation operation 51,... In the polling operation 50,. , CH1 frame 201 cannot be received at all. Moreover, in the first polling operation 50 after shifting to the transmission timing of the CH2 frame 202 (in FIG. 7, the polling operation 50 is included in the transmission timing of the second CH2 frame 202 from the beginning). Due to the presence of the format noise 41f, the CH1 reception preparation operation 51 erroneously receives the format noise 41f during the CH1 data (noise) reception operation 51b of the frame length ΔTf. Therefore, in the in-vehicle communication control apparatus, as shown in FIG. 7, the CH2 reception preparation operation is performed immediately after the CH1 data reception operation 51b, regardless of the polling operation 50,... Periodically performed at the polling period ΔTp. Then, the start bit of the third CH2 frame 202 from the beginning is searched during the start bit search operation 52a of ΔTfm1 [sec].

  However, acquisition of bit data (ID code, function code, etc.) from the second CH2 frame 202 as well as the subsequent third CH2 frame 202 from the first CH2 frame 202 is also possible. Since it is received from the middle of the same CH2 frame 202, it is not successful. In FIG. 7, start bit search time ΔTfm1 <frame length ΔTf.

  Thereafter, as shown in FIG. 7, the start bit search operation 52 a detects the start bit of the fourth (last) CH2 frame 202 from the first CH2 frame 202 and is included in the CH2 frame 202. Bit data is acquired as received data.

  Note that even under this technique, in the case of not being in the worst state as shown in FIG. 7, that is, for example, in-vehicle communication after shifting to the transmission timing of the CH2 frame 202 as shown in FIG. When the first polling operation 50 by the control device is included in the transmission timing of the first (first) CH2 frame 202, the CH1 reception preparation operation is performed due to the presence of the format noise 41f as in the state of FIG. 51, the format noise 41f is erroneously received during the CH1 data reception operation 51b of the frame length ΔTf, but the second CH2 frame 202 following the first (first) CH2 frame 202 starts its start. Bit detection is performed normally, and acquisition of bit data from the CH2 frame 202 is successful. In FIG. 8, start bit search time ΔTfm2 <frame length ΔTf.

  Thus, in the conventional example, assuming the worst state as shown in FIG. 7 in the presence of environmental noise belonging to the frequency band of CH1, when receiving the CH2 frame 202, a total of 4 Of the two CH2 frames 202,..., Bit data is acquired for the first time in the fourth (last) CH2 frame 202. Therefore, in the conventional example, the reception of the bit data included in the CH2 frame 202 is completed accordingly, that is, in the electronic key system, it takes a long time to establish wireless communication, and the data signal Swkb is transmitted in the electronic key. As a result, since it is necessary to transmit a total of seven frames 201,..., 202,.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a multi-channel communication system and a multi-channel communication system in which power consumption required for wireless communication is reduced and wireless communication is established in a short time. To provide an electronic key system employing a channel communication system.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a transmission means capable of transmitting radio waves through a plurality of channels and a radio wave transmitted from the transmission means by performing a polling operation at a certain period. Receiving means capable of receiving the first channel frame and continuously transmitting a plurality of first channel frames each including bit data on the first channel, and then receiving the first channel radio wave. Multi-channel communication in which a plurality of second channel frames each including bit data are continuously transmitted on a second channel having a frequency different from that of the first channel in order to establish wireless communication even in a disturbing noise environment. In the system, a dummy bit is added to the bit data included in each second channel frame to extend the frame length of each second channel frame. Things, and the gist.

  According to this configuration, in the transmission means, dummy bits are added to the bit data included in each second channel frame to extend the frame length of each second channel frame. For this reason, in the receiving means, when reception of the first channel frame is disturbed by environmental noise, and bit data is not acquired from the first channel frame, the time length of the dummy bits included in the second channel frame, The second and subsequent second channel frames are transmitted with a delay from the transmitting means. Thus, when the receiving unit is configured to receive the first or second channel frame by performing a polling operation at a certain period, the second channel capable of receiving the entire bit data from the transmitting unit. Frames are transmitted early, and early establishment of wireless communication is achieved.

  According to a second aspect of the present invention, in the multi-channel communication system according to the first aspect, the period ΔTp of the polling operation by the receiving unit for confirming whether or not the radio wave is transmitted from the transmitting unit, and the second The ratio ΔTp / (ΔTf + α) to the frame length ΔTf of the channel frame (where α is the time length [sec] of the dummy bit) is set in a range of 1.0 ≦ ΔTp / (ΔTf + α) ≦ 1.4 It is a summary.

  According to this configuration, the ratio ΔTp / (ΔTf + α) between the period ΔTp of the polling operation by the receiving unit for confirming whether or not the radio wave is transmitted from the transmitting unit and the frame length (ΔTf + α) of each second channel frame is 1.0 ≦ ΔTp / (ΔTf + α) ≦ 1.4 is set. For this reason, the ratio between the period ΔTp of the polling operation and the frame length (ΔTf + α) of each second channel frame is optimized, so that early establishment of wireless communication and reduction of power consumption required for the polling operation are effective. To be compatible.

  According to a third aspect of the present invention, in the multi-channel communication system according to the second aspect, each polling operation includes a first channel reception preparation operation for preparing bit data reception of the first channel, and a second channel. A second channel reception preparation operation for preparing bit data reception of the first channel, and the reception means receives environmental noise that interferes with reception of the bit data of the first channel by the first channel reception preparation operation. Thus, when the second channel bit data cannot be received for a predetermined time, the second channel bit data is received after the predetermined time regardless of the polling operation.

  According to the configuration, each polling operation includes a first channel reception preparation operation for preparing bit data reception of the first channel and a second channel reception preparation operation for preparing bit data reception of the second channel. include. For this reason, in each polling operation, when bit data (radio waves) cannot be received on the first channel, bit data (radio waves) can be effectively received on the second channel. Further, when the receiving means cannot receive the radio wave of the second channel for a predetermined time by receiving the environmental noise that interferes with the reception of the bit data of the first channel by the first channel reception preparation operation, the receiver is involved in the polling operation. First, the radio wave of the second channel is received after the predetermined time has elapsed. For this reason, when reception of the first channel radio wave is hindered by environmental noise, it is possible to reliably receive the second channel radio wave after a predetermined time has elapsed.

  According to a fourth aspect of the present invention, in the multi-channel communication system according to any one of the first to third aspects, the dummy bit is not added to the bit data included in each second channel frame. In the case where the receiving means cannot complete the reception of the n-th (n is a natural number of 2 or more) second channel frame from the first transmitted second channel frame, the n-th The gist is that a time length of a dummy bit is set in each second channel frame so that reception of the second channel frame can be completed.

  According to the configuration, if the dummy bit is not added to the bit data included in each second channel frame, the receiving means calculates the nth (n is n) from the second channel frame transmitted first. (Natural number greater than or equal to 2) The time length of the dummy bit added to the bit data in each second channel frame so that the reception of the nth second channel frame can be completed when the reception of the nth second channel frame cannot be completed. Is set. Therefore, the transmission means can receive each second channel frame at an early stage from the time when the transmission frequency of the radio wave (frame) is switched from the first channel to the second channel.

  The invention according to claim 5 performs wireless communication between an electronic key possessed by a user of the vehicle and an in-vehicle communication control device mounted on the vehicle, and collates an ID code transmitted by the wireless communication. An electronic key system that permits or executes a door locking / unlocking operation and an engine start / stop operation of the vehicle via the multi-channel communication system according to any one of claims 1 to 4. The electronic key is the transmission means, the in-vehicle communication control device is the reception means, and the ID code is included in the bit data transmitted in the first channel and the second channel. The gist of this is

  According to this configuration, the multi-channel communication system described above is used in an electronic key system that permits or executes a door locking / unlocking operation and an engine start / stop operation via wireless communication between the electronic key and the vehicle. For this reason, in such an electronic key system, the transmission time by the electronic key is shortened, and the power consumption required for radio wave transmission by the electronic key is realized, and the electronic key is connected between the electronic key and the in-vehicle communication control device. Wireless communication is established in a short time. Thus, the door locking / unlocking operation and the engine start / stop operation of the vehicle can be quickly and automatically performed without causing the vehicle user to feel stress.

  According to the multi-channel communication system of the present invention, power consumption required for wireless communication is reduced, and wireless communication is established in a short time.

Hereinafter, embodiments of the multi-channel communication system of the present invention will be described with reference to the drawings.
As shown in FIG. 1, an electronic key system 1 according to this embodiment includes an electronic key 2 as a transmission means capable of transmitting radio waves on two (plural) channels (here, CH1 and CH2), and a certain period. At a (predetermined period), a polling operation for confirming the presence / absence of transmission of control radio waves (radio waves transmitted by CH1 and CH2) from the electronic key 2 is performed, and a plurality of channels ( Here, the vehicle-mounted communication control apparatus 3 as a receiving means which can receive the radio waves of CH1, CH2) is provided. The electronic key system 1 is provided in a vehicle 30 that is a four-wheeled vehicle, and the doors 30a and 30a of the vehicle 30 are locked and unlocked by a switch operation of the electronic key 2.

  The electronic key 2 is provided with a communication control unit 21 for controlling various functions of the electronic key 2. The communication control unit 21 includes a CPU (Central Processing Unit) 22 and a memory 23 connected thereto, and operates the electronic key 2 based on a control program stored in the memory 23.

  The communication control unit 21 is electrically connected to a locking switch 2a for locking the doors 30a, 30a of the vehicle 30 and an unlocking switch 2b for unlocking the doors 30a, 30a of the vehicle 30. The communication control unit 21 is electrically connected to a transmission circuit 24 having an antenna 24a for modulating a predetermined signal into a radio wave (here, a UHF band radio wave) and transmitting the signal to the outside.

  When the lock switch 2a is operated, the communication control unit 21 transmits the lock request signal Slk from the transmission circuit 24 to the vehicle 30 as a radio wave, and sets the doors 30a and 30a to the locked state. On the other hand, when the unlocking switch 2b is operated, the unlocking request signal Sul is transmitted from the transmitting circuit 24 to the vehicle 30 as a radio wave, and the doors 30a and 30a are brought into the unlocking state. Here, the lock request signal Slk and the unlock request signal Sul constitute the data signal Swka.

  The in-vehicle communication control device 3 is mounted on the vehicle 30. The in-vehicle communication control device 3 receives a radio wave (in this case, a radio wave in the UHF band) from the electronic key 2 via the antenna 31a and receives a data signal Swka (lock request signal Slk or unlock request signal Sul). A tuner (in-vehicle communication device) 31 for demodulating is provided. The tuner 31 has a verification ECU (Electric Control Unit) 32 for controlling various functions such as verification of an ID code transmitted from the electronic key 2 and an ID code unique to the vehicle 30. Electrically connected. A door ECU (door locking / unlocking control device) 35 for controlling the locking / unlocking operation of the doors 30a, 30a is electrically connected to the verification ECU 32. The door ECU 35 is connected to a door lock motor 35a as a drive source of a dead bolt (not shown) for locking the doors 30a and 30a. The collation ECU 32 includes a CPU (central processing unit) 33 and a memory 34 connected thereto, and operates the in-vehicle communication control device 3 based on a control program stored in the memory 34.

  When the communication control unit 21 detects that the locking switch 2a or the unlocking switch 2b is operated, the data signal Swka corresponding to the switch operation is transmitted from the transmission circuit 24 via the antenna 24a in the UHF band. Wireless transmission to the outside. Specifically, when the communication control unit 21 detects that the locking switch 2a is operated, the communication control unit 21 wirelessly transmits a locking request signal Slk as the data signal Swka to the vehicle 30 via the transmission circuit 24 and the antenna 24a. When it is detected that the unlocking switch 2b is operated, the unlocking request signal Sul as the data signal Swka is wirelessly transmitted to the vehicle 30 via the transmission circuit 24 and the antenna 24a.

  On the other hand, when the verification ECU 32 receives the data signal Swka (locking request signal Slk or unlocking request signal Sul) from the electronic key 2 via the tuner 31, if the ID code can be verified, the verification signal 32 The door lock motor 35a is operated via the door ECU 35 according to the contents. Specifically, when the verification ECU 32 receives the lock request signal Slk, and the ID code can be verified, if the door 30a, 30a is unlocked at this time, the door lock motor 35a is operated to open the door 30a, When the unlocking request signal Sul is received, the verification ECU 32 receives the unlock request signal Sul. When the ID code can be verified, if the doors 30a and 30a are locked at this time, the door lock motor 35a Is operated so that the doors 30a and 30a can be unlocked.

  In this embodiment, as shown in FIG. 2, this data signal Swka is data in which six (plural) CH1 and CH2 frames 101,..., 102,. It has a format.

  6 (plural) CH1 frames 101,..., CH2 frames 102,... Are transmitted by the vehicle 30 based on the presence of electronic keys having similar transmission frequencies and the influence of environmental noise. 3, it is assumed that the CH1 or CH2 frames 101 and 102 are received from the middle. Therefore, by receiving any of the CH1 or CH2 frames 101 and 102 in a complete state, the bit data included in the CH1 or CH2 frames 101 and 102 is received. This is for receiving the whole.

  In other words, if the bit data included in each frame 101 (102) can be acquired in a complete state even from one frame 101 (102) of the plurality of CH1 frames 101,. Thereby, the data signal Swka (the lock request signal Slk or the unlock request signal Sul) is received by the verification ECU 32 via the tuner 31, and the reception of the data signal Swka is completed.

  Further, in this way, even if the wireless communication is disturbed by the environmental noise in the analogy CH1, the wireless communication is normally performed in the CH2 having a frequency different from that of the CH1 without being disturbed by the environmental noise, and the wireless communication is established. The accuracy of this will be improved.

  Specifically, as shown in FIG. 2, each CH1 frame 101 includes a start bit 101a for notifying the in-vehicle communication control device 3 of the start of data transmission, and an ID code 101b as a code unique to each electronic key. The rolling code 101c whose code changes each time the lock switch 2a or the unlock switch 2b is operated, the lock request signal Slk for locking the doors 30a, 30a, or the doors 30a, 30a to be unlocked. A function code 101d as specific command contents of the unlock request signal Sul and a stop bit 101e for distinguishing from the next start bit are integrally included as bit data. The stop bit 101e is also necessary for the in-vehicle communication control device 3 to obtain data processing time.

  Each CH2 frame 102 includes a start bit 102a for notifying the vehicle-mounted communication control device 3 of the start of data transmission, an ID code 102b as a code unique to each electronic key 2, a lock switch 2a, and an unlock switch 2b. The rolling code 102c whose code changes each time the button is operated, the lock request signal Slk for bringing the doors 30a and 30a into the locked state, or the unlock request signal Sul for bringing the doors 30a and 30a into the unlocked state The time length α [sec] composed of a function code 102d as a detailed command content, a stop bit 102e for distinguishing from the next start bit, and a code meaningless in controlling various in-vehicle devices in the electronic key system 1 Dummy bits 102f are integrally included as bit data. The stop bit 102e is also necessary for the in-vehicle communication control device 3 to obtain the data processing time, like the stop bit 101e of the CH1 frame 101. As described above, in this embodiment, dummy bits 102f are added to the bit data included in each CH2 frame 102 transmitted by CH2, and the frame length of each CH2 frame 102 is set to α [sec] as compared with the CH2 frame 102. It is stretched for minutes.

  Therefore, in each frame 101 (102), the start bit 101a (102a) is read by the in-vehicle communication control device 3 to recognize the head of each frame 101 (102), and the subsequent ID code 101b (102b) and rolling The electronic key 2 is collated by collating the code 101c (102c) with that on the vehicle 30 side, and whether the key operation of the electronic key 2 is a locking operation or a releasing operation by the subsequent function code 101d (102d) Determine. The ID code 101b (102b) and the rolling code 101c (102c) are composed of data groups stored in the memory 23 of the communication control unit 21.

  The in-vehicle communication control device 3 receives any one of the CH1 and CH2 frames 101,..., 102,... In a complete state from the start bit 101a (102a) at the head to the stop bit 101e (102e) at the end. The lock request signal Slk or the unlock request signal Sul is received by the in-vehicle communication control device 3, and the reception of the data signal Swka is completed. That is, as a result, in the electronic key system 1, wireless communication is established between the electronic key 2 and the in-vehicle communication control device 3.

  In this embodiment, the operation example of the electronic key system 1 as a multi-channel communication system will be further described with reference to FIG. 3. As shown in FIGS. 1 to 3, in the electronic key 2, the lock switch 2 a and unlocking are performed. When the switch 2b is operated, the electronic key 2 transmits a data signal Swka (locking request signal Slk or unlocking request signal Sul) including a command content (locking command or unlocking command) corresponding to the switch operation. Transmit from circuit 24.

  The electronic key 2 transmits the bit data of each frame 101 (102) when wirelessly transmitting the data signal Swka comprising the total of CH1 and CH2 frames 101,..., 102,. It modulates and transmits to the radio wave of a specific frequency (CH1, CH2). Here, the frame length (frame time length) of each frame 101 (102) is set to ΔTf [sec] similarly to each frame 201 (202).

  In the example shown in FIG. 3, the electronic key 2 first transmits the bit data of three (plural) CH1 frames 101,... Continuously in time series at the CH1 frequency, and then further transmits at the CH2 frequency. Bit data of three (plural) CH2 frames 102,... Are wirelessly transmitted in time series. That is, in the electronic key 2, when the locking switch 2a or the unlocking switch 2b is operated, three CH1 frames 101,... Continue, and subsequently, three more CH2 frames 102,. The data signal Swka is transmitted to the vehicle 30.

  On the other hand, in FIG. 3, the in-vehicle communication control device 3 performs a polling operation 50 for confirming the presence / absence of transmission of control radio waves (radio waves transmitted by CH 1 and CH 2) from the electronic key via the tuner 31. It is performed with a short time period (polling period ΔTp [sec]) of about 300 msec. In this polling operation 50, first, a CH1 reception preparation operation 51 for CH1 bit data reception preparation is performed for a predetermined time (about several tens of milliseconds [sec]), and then CH2 for CH2 bit data reception preparation. The reception preparation operation 52 is performed for a predetermined time (several tens of millimeters [sec]). The CH1 reception preparation operation 51 and the CH2 reception preparation operation 52 mean operations for tuning the reception frequency to the transmission frequencies assigned to CH1 and CH2, respectively, in the in-vehicle communication control device 3.

  Here, as shown in FIG. 3, at the transmission timing of the CH1 frame 201 three times in total, the random noise 41r that is the environmental noise belonging to the frequency band of CH1 exists, and the CH2 frame 202 three times in total. Assume that there is a format noise 41f (frequency transmitted from the same kind of electronic key, regular noise with constant intensity) that is an environmental noise belonging to the CH1 frequency band at the transmission timing. In this state, in the background art, as in the state shown in FIG. 7, the wireless communication performed in the electronic key system 1 including the electronic key 2 and the in-vehicle communication control device 3 is almost completely caused by environmental noise. Assume the worst situation that will be disturbed.

  In this state, similarly to the state shown in FIG. 7, the in-vehicle communication control device 3 is disturbed by the random noise 41r, and the in-vehicle communication control device 3 performs the CH1 reception preparation operation 51,... In the polling operation 50,. Cannot receive the CH1 frame 101 at all. Moreover, in the first polling operation 50 after shifting to the transmission timing of the CH2 frame 102 (in FIG. 3, the polling operation 50 is included in the transmission timing of the second CH2 frame 102 from the beginning). Due to the presence of the format noise 41f, the CH1 reception preparation operation 51 erroneously receives the format noise 41f during the CH1 data reception operation 51b with the frame length ΔTf. This is because the in-vehicle communication control device 3 requires a time of about the frame length ΔTf of the CH1 frame 101 for checking whether or not the bit data transmitted in the state formatted in the CH1 is authentic. is there. For this reason, in the in-vehicle communication control device 3, as shown in FIG. 3, the CH2 reception preparation operation 52 immediately after the CH1 data reception operation 51b, regardless of the polling operation 50,... Periodically performed at the polling period ΔTp. Then, the start bit of the CH2 frame 102 is searched during the start bit search operation 52a of ΔTfm3 [sec].

  In this embodiment, unlike the CH2 frame 202 shown in FIG. 7, dummy bits 102f each having a time length α [sec] are added to the bit data of each CH2 frame 102 (see FIG. 2). For this reason, in the case of the background art shown in FIG. 7, as described above, the second CH2 frame 202 is calculated from the first CH2 frame 202, and the bit data ( Acquisition of ID code, function code, etc.) was not successful because it was received from the middle of the CH2 frame 202. On the other hand, in this embodiment, as shown in FIG. 3, dummy bits included in each CH2 frame 102 even in the worst state for wireless communication performed between the electronic key 2 and the vehicle 30. Since the second and subsequent CH2 frames 102 are transmitted with a time length α [sec] of 102f with a delay, the CH2 frame 102 that can receive the entire bit data from the electronic key 2 is early. Will be sent. Specifically, at the transmission timing of the second CH2 frame 102 from the beginning, due to the presence of the format noise 41f, the CH1 reception preparation operation 51 causes the format noise 41f to be mistakenly generated during the CH1 data reception operation 51b with the frame length ΔTf. I receive it. However, since the start bit of the CH2 frame 102 is searched during the start bit search operation 52a of ΔTfm3 [sec] before the transmission timing of the third (last) CH2 frame 102 from the beginning, the CH2 frame 102 Will be received in perfect condition. That is, the entire bit data included in the CH2 frame 102 is received during the frame length ΔTf by the CH2 data receiving operation 52b. In the vehicle 30, when the ID code of the vehicle 30 and the electronic key 2 can be verified via the in-vehicle communication control device 3, and the ID code can be verified, the data signal Swka (the lock request signal Slk or The vehicle control operation (locking operation or unlocking operation) of the doors 30a, 30a in accordance with the command content (locking command or unlocking command) of the unlock request signal Sul is realized at an early stage. As a result, early establishment of wireless communication is achieved. In FIG. 3, start bit search time ΔTfm3 <frame length ΔTf.

  In this embodiment, the ratio ΔTp / the ratio of the period ΔTp of the polling operation by the in-vehicle communication control device 3 for confirming whether or not radio waves are transmitted from the electronic key 2 to the frame length (ΔTf + α) of each CH2 frame 102. (ΔTf + α) may be set in a range of 1.0 ≦ ΔTp / (ΔTf + α) ≦ 1.4, more preferably in a range of 1.1 ≦ ΔTp / (ΔTf + α) ≦ 1.3. Thereby, the ratio between the period of the polling operation 50 and the frame length (ΔTf + α) of each CH2 frame 102 is optimized, and early establishment of wireless communication between the electronic key 2 and the in-vehicle communication control device 3 Reduction of power consumption required for the polling operation 50 can be effectively achieved at the same time. Specifically, if the ratio ΔTp / (ΔTf + α) is less than 1.0, the frequency of the polling operation 50 increases excessively, and the power consumption required for the polling operation 50 may become excessive. On the other hand, if the ratio ΔTp / (ΔTf + α) exceeds 1.4, the frequency of the polling operation 50 is excessively reduced, and establishment of wireless communication is delayed between the electronic key 2 and the in-vehicle communication control device 3, or Wireless communication may not be established at all.

  In the present embodiment, when the dummy bit 102f is not added to the bit data included in each CH2 frame 102, that is, in the case of the CH2 frame 202 shown in FIG. When the reception of the third (n) (n is a natural number equal to or greater than 2) -th CH2 frame 102 from the CH2 frame 102 transmitted first cannot be completed, the third (n) -th CH2 frame 102 In each of the CH2 frames 102, the time length α [sec] of the dummy bit 102f is set so that the reception can be completed. Specifically, the time length α is preferably set as appropriate in the range of 10 msec to 50 msec.

According to the electronic key system 1 of the present embodiment, the following operations and effects can be obtained.
(1) In the electronic key 2, a dummy bit 102f is added to the bit data included in each CH2 frame 102 to extend the frame length (ΔTf + α) [sec] of each CH2 frame 102. For this reason, in the in-vehicle communication control device 3, when the reception of the CH1 frame 101 is obstructed by the environmental noise and the bit data is not acquired from the CH1 frame 101, the time length α [ sec], the second and subsequent CH2 frames 102 are transmitted from the electronic key 2 with a delay. As a result, when the in-vehicle communication control device 3 receives the CH1 or CH2 frames 101 and 102 by performing the polling operation 50 at a constant cycle (polling cycle ΔTp), the bit data from the electronic key 2 is received. As a result, the CH2 frame 102 that can be received in its entirety is transmitted at an early stage, and early establishment of wireless communication is achieved.

  (2) Since the number of frames transmitted by the electronic key 2 as the data signal Swk is changed from seven to six, the power consumption required for transmission / reception of radio waves by the electronic key 2 can be reduced. As a result, the life of the battery of the electronic key 2 that is normally driven by a battery is extended, and the frequency of battery replacement is also reduced.

  (3) A ratio ΔTp / () between the period ΔTp of the polling operation 50 by the in-vehicle communication control device 3 for confirming whether or not radio waves are transmitted from the electronic key 2 and the frame length (ΔTf + α) [sec] of each CH2 frame 102 ΔTf + α) is set in a range of 1.0 ≦ ΔTp / (ΔTf + α) ≦ 1.4. For this reason, the ratio between the period ΔTp of the polling operation 50 and the frame length ΔTf of each second channel frame is optimized, and early establishment of wireless communication and reduction of the power consumption required for the polling operation 50 are effective. To be compatible.

  (4) Each polling operation 50 includes a CH1 reception preparation operation 51 for preparing CH1 bit data reception and a CH2 reception preparation operation for preparing CH2 bit data reception. For this reason, in each polling operation 50, when bit data (radio wave) cannot be received on CH1, bit data (radio wave) can be effectively received on the second channel. Furthermore, the in-vehicle communication control device 3 cannot receive the CH2 bit data of the frame length ΔTf (predetermined time) of the CH2 frame 101 by receiving environmental noise that interferes with the reception of the CH1 bit data by the CH1 reception preparation operation. In this case, regardless of the polling operation 50, the radio wave of CH2 is received after a lapse of time corresponding to the frame length ΔTf. For this reason, when reception of the first channel radio wave is hindered by environmental noise, it is possible to reliably receive the CH2 radio wave after a lapse of time corresponding to the frame length ΔTf.

  (5) If the dummy bit 102f is not added to the bit data included in each CH2 frame 102, the in-vehicle communication control device 3 calculates the third (n) th from the CH2 frame 102 transmitted first. When the reception of the second frame 102 cannot be completed, the time length α [sec] of the dummy bit 102f added to the bit data in each CH2 frame 102 so that the reception of the third (n) th CH2 frame 102 can be completed. ] Is set. Therefore, the electronic key 2 can receive each CH2 frame 102 at an early stage from the time when the transmission frequency of the radio wave (frame) is switched from CH1 to CH2.

  (6) Reduction of transmission time by the electronic key 2 (see ΔTs shown in FIG. 3), saving of power consumption required for radio wave transmission in the electronic key 2, and realization of the electronic key 2 and the in-vehicle communication control device 3 Wireless communication performed between the two is established in a short time. Thereby, the door locking / unlocking operation of the vehicle 30 is quickly and automatically performed without the user of the vehicle 30 feeling stressed.

The above embodiment may be modified as follows.
In the above embodiment, the dummy bit 102f is added to the end of each CH2 frame 102. However, the present invention is not limited to this, and the dummy bit 102f can be added to the head or midway of the CH2 frame 102 as long as the establishment of wireless communication is not unduly delayed.

  In the above embodiment, the dummy bit 102f is added to the bit data of three (all) CH2 frames 102,. However, the present invention is not limited to this, and the dummy bit 102f can be added only to the bit data of a part (for example, the second one from the beginning) of the CH2 frame 102.

  In the above embodiment, various on-vehicle devices (door locking / unlocking control device [door ECU 35], engine start / stop control device [engine ECU]) mounted on the vehicle 30 that are transmitted from the electronic key 2 to the on-vehicle communication control device 3 As the data signal Swka that is a signal used for control, the lock request signal Slk for making the door lockable or the unlock request signal Sul for making the doors 30a and 30a unlockable is illustrated. . However, the present invention is not limited to this, and the data signal Swka can be exemplified by an engine start permission request signal for making the engine startable and an engine start permission request signal for making the engine stoppable. . Furthermore, the present invention is not limited to this, and the data signal Swka is not limited to that for enabling the operation of the various in-vehicle devices, and may be for executing the operations of the various in-vehicle devices.

  In the above embodiment, the multi-channel communication system is used in the electronic key system 1 that is provided in the vehicle 30 that is a moving body and includes the electronic key 2 and the in-vehicle communication control device 3, but is not limited thereto. The multi-channel communication system can of course be used for an electronic key system provided in a house or the like that is a real estate.

  In the above embodiment, the dummy bit 102f added to the bit data of the CH2 frame 102 is configured by a meaningless code for controlling various in-vehicle devices in the electronic key system 1. However, the present invention is not limited to this, and the electronic key system 1 may be configured by a code having some meaning in the control of various in-vehicle devices.

  In the above embodiment, the electronic key system 1 is a so-called remote control type (one-way communication method from the electronic key 2 to the vehicle 30), but a two-way communication method between the electronic key 2 and the vehicle 30. It is also possible to apply to the electronic key system.

1 is an overall configuration diagram of an electronic key system according to an embodiment of the present invention. The block diagram of the data signal Swka which concerns on embodiment of this invention (The dummy bit is not added to the last CH2 frame). The time chart figure which shows the transmission / reception state of the data signal Swka which concerns on embodiment of this invention. The block diagram of the data signal Swkb which concerns on a prior art example. The time chart figure which shows the transmission / reception state of the data signal Swkb which concerns on a prior art example. The time chart figure which shows another transmission / reception state of the data signal Swkb which concerns on a prior art example. The time chart figure which shows another transmission / reception state of the data signal Swkb concerning a prior art example. The time chart figure which shows another transmission / reception state of the data signal Swkb concerning a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 2 ... Electronic key, 3 ... Vehicle-mounted communication control apparatus, 30 ... Vehicle, 50 ... Polling operation, 102f ... Dummy bit.

Claims (5)

A transmission unit capable of transmitting radio waves on a plurality of channels, and a reception unit capable of receiving radio waves transmitted from the transmission unit by performing a polling operation at a certain period;
The transmission means continuously transmits a plurality of first channel frames each including bit data on the first channel, and then establishes wireless communication even in a noise environment that interferes with reception of radio waves on the first channel. Therefore, in a multi-channel communication system in which a plurality of second channel frames each including bit data are continuously transmitted on a second channel having a frequency different from that of the first channel.
A multi-channel communication system, wherein dummy bits are added to bit data included in each second channel frame to extend the frame length of each second channel frame. The multi-channel communication system according to claim 1, wherein
Ratio ΔTp / (ΔTf + α) between the period ΔTp of the polling operation by the receiving means for confirming whether or not radio waves are transmitted from the transmitting means and the frame length ΔTf of each second channel frame (where α is a dummy) A multi-channel communication system in which a bit time length [sec]) is set in a range of 1.0 ≦ ΔTp / (ΔTf + α) ≦ 1.4. The multi-channel communication system according to claim 2,
Each of the polling operations includes a first channel reception preparation operation for preparing bit data reception of the first channel and a second channel reception preparation operation for preparation of bit data reception of the second channel, When the reception means cannot receive the second channel bit data for a predetermined time by receiving environmental noise that interferes with reception of the first channel bit data by the first channel reception preparation operation, the polling operation is performed. Regardless of whether the second channel bit data is received after the predetermined time has elapsed. In the multi-channel communication system according to any one of claims 1 to 3,
In the case where the dummy bit is not added to the bit data included in each second channel frame, the receiving means calculates the nth (n is a natural number equal to or greater than 2) from the second channel frame transmitted first. ) The dummy bit time length is set in each second channel frame so that the reception of the nth second channel frame can be completed when the reception of the second second channel frame cannot be completed. Multi-channel communication system. Wireless communication is performed between an electronic key possessed by a user of the vehicle and an in-vehicle communication control device mounted on the vehicle, and the door locking / unlocking of the vehicle is performed through the verification of an ID code transmitted by the wireless communication. An electronic key system that permits or executes operations and engine start / stop operations,
A multi-channel communication system according to any one of claims 1 to 4 is used,
The electronic key is the transmission means, the in-vehicle communication control device is the reception means, and the ID code is included in bit data transmitted in the first channel and the second channel. An electronic key system characterized by that.

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