JP4303136B2 - Communication device, portable device, and communication system - Google Patents

Description

  The present invention relates to a communication device that transmits a request signal to establish bidirectional communication with a portable device, and an ID code that is individually set for each portable device in response to a request signal transmitted from the communication device. The present invention relates to a portable device that transmits a signal including the communication device and a communication system that includes the communication device and the portable device.

  In recent years, in automobiles, a smart key system having a smart entry function has been proposed for the purpose of achieving both improvement in security level and improvement in convenience (see, for example, Patent Document 1). Here, the smart entry function is a function for permitting unlocking of the in-vehicle door when a driver having a corresponding smart key enters a predetermined area outside the vehicle. In addition, when the door outside handle is touched in such a state where unlocking of the vehicle-mounted door is permitted, the vehicle-mounted door is unlocked.

  That is, the smart key system includes a smart key possessed by the driver, that is, a portable device and a door unlock control device provided on the automobile side. In the portable device, an ID code individually set for each portable device is stored. On the other hand, the door unlock control device stores the same ID code (vehicle side ID code) as the ID code of the corresponding portable device. Then, the smart entry function is activated and unlocking of the vehicle-mounted door is permitted on the condition that the two ID codes are matched by bidirectional communication between the portable device and the door unlock control device.

  Specifically, a request signal is transmitted from the door unlock control device to a predetermined area outside the vehicle in a state in which the vehicle-mounted door is locked in order to monitor the approach of the driver carrying the corresponding portable device. . Then, based on the fact that the driver carrying the corresponding portable device has entered a predetermined area outside the vehicle, a signal including an ID code is transmitted from the portable device in response to the request signal. It is determined by the lock control device whether the ID code of the portable device and the ID code on the automobile side match. Then, on the condition that both ID codes match, the smart entry function is enabled and the unlocking of the in-vehicle door is permitted.

When the smart entry function is used in this way, it is not necessary to perform any complicated key operation when boarding. Therefore, convenience can be improved. Moreover, the vehicle-mounted door cannot be unlocked unless a portable device that is significantly more difficult to duplicate than conventional mechanical keys is possessed. Therefore, the security level can be improved.
JP 2002-029385 A

  By the way, the portable device provided for the smart entry function includes a battery as a power source for transmitting a signal including an ID code in response to the request signal as described above. Here, the voltage level of the transmission signal from the portable device is fixed regardless of the quality of the communication environment. That is, the voltage level is set high so that suitable communication can be performed even in an environment where the communication state is poor.

  However, in an environment where the communication state is good, suitable communication can be performed even if the voltage level is set low. Nevertheless, the voltage level is set higher in advance in consideration of communication in an environment where the communication state is poor. In other words, in an environment where the communication state is good, the current voltage level is more than necessary. For this reason, the configuration in which the voltage level is fixed regardless of whether the communication environment is good or not is not necessarily appropriate from the viewpoint of suppressing the battery power consumption of the portable device.

  The present invention has been made paying attention to such problems, and an object thereof is to provide a communication device, a portable device, and a communication system capable of performing suitable communication in accordance with a communication environment. There is.

  In order to achieve the above object, according to the first aspect of the present invention, in the communication device including a first transmission unit that transmits a request signal to establish bidirectional communication with the portable device, the request signal includes: And a first generation unit configured to generate a plurality of indicator signals having different voltage levels as indicators when the voltage level of the signal transmitted from the portable device in response is determined on the portable device side; The means is characterized in that the plurality of indicator signals generated by the first generation means are added to the request signal and transmitted.

  In the second aspect of the present invention, the portable device includes a second transmission unit that transmits an ID code signal including an ID code individually set for each portable device in response to a request signal transmitted from the communication device. A determination means for determining a voltage level in the case of transmitting the ID code signal using a plurality of index signals having different voltage levels transmitted as a result of being added to the request signal, and determined by the determination means And a second generation means for generating the ID code signal having the voltage level set, wherein the second transmission means transmits the ID code signal generated by the second generation means.

  According to a third aspect of the present invention, in the portable device according to the second aspect, the portable device includes a receiving unit that receives the plurality of indicator signals, and the determining unit includes a plurality of indicator signals received by the receiving unit. An index signal having the lowest voltage level is selected, and the voltage level of the selected index signal is determined as the voltage level for transmitting the ID code signal.

  According to a fourth aspect of the present invention, in the portable device according to the second aspect of the present invention, the portable device includes a receiving unit that receives the plurality of indicator signals, and the determining unit includes a plurality of indicator signals received by the receiving unit. An index signal having the second lowest voltage level is selected, and the voltage level of the selected index signal is determined as the voltage level for transmitting the ID code signal.

According to a fifth aspect of the present invention, the communication apparatus according to the first aspect and the portable device according to any one of the second to fourth aspects are provided.
The “action” of the present invention will be described below.

  When two-way communication is performed between the communication device according to the invention according to claim 1 and the portable device according to any one of claims 2 to 4, the first of the communication devices A plurality of index signals having different voltage levels are generated by the generating means. Then, the plurality of indicator signals generated by the first generation unit are added to the request signal and transmitted by the first transmission unit of the communication apparatus.

  Then, using a plurality of indicator signals having different voltage levels transmitted as a result of being added to the request signal in this way, an ID code individually set for each portable device by the portable device determination means is included. The voltage level for transmitting the ID code signal is determined. Then, the ID code signal having the voltage level determined by the determination unit is generated by the second generation unit of the portable device. Then, the ID code signal generated by the second generation unit is transmitted by the second transmission unit of the portable device.

  Here, the voltage level of the transmission signal from the portable device is not fixed regardless of whether the communication environment is good or bad, and the voltage level is determined using the plurality of indicator signals as indicators. For this reason, it becomes possible to arbitrarily set the voltage level according to the quality of the communication environment.

Since this invention is comprised as mentioned above, there exist the following effects.
According to the invention according to any one of claims 1 to 5, it is possible to perform suitable communication in accordance with the communication environment.

Hereinafter, an embodiment in which the present invention is embodied in an automobile smart key system will be described.
As shown in FIG. 1, the smart key system 1 includes a portable device 2 and a door unlock control device 3. The portable device 2 is carried by the driver. The portable device 2 of the present embodiment is a wristwatch type and is mounted so as to surround the driver's arm. When the portable device 2 is thus mounted, the back surface of the portable device 2 is in close contact with the driver's arm. On the other hand, the door unlock control device 3 is provided on the automobile side. The smart key system 1 is configured to allow two-way communication between the portable device 2 and the door unlock control device 3. In the smart key system 1 according to the present embodiment, when the driver wearing the portable device 2 touches the door outside handle 21, the driver's human body is transmitted between the portable device 2 and the door unlock control device 3. Communication within the human body is possible.

  The portable device 2 has a reception function and a transmission function. The portable device 2 includes a reference potential electrode 11, a communication electrode 12, a reception circuit 13, a microcomputer 14, and a transmission circuit 15. The reference potential electrode 11 is exposed on the back surface of the portable device 2. The reference potential electrode 11 is grounded via the driver's human body when the portable device 2 is mounted on the driver's arm as described above. On the other hand, similarly to the reference potential electrode 11, the communication electrode 12 is exposed on the back surface of the portable device 2.

  The receiving circuit 13 is for receiving a request signal transmitted from the door unlock control device 3 and an index signal described later. When the driver wearing the portable device 2 touches the door outside handle 21, the receiving circuit 13 of the present embodiment receives the request signal and the index signal from the door unlock control device 3 and the driver's human body and the communication electrode 12. Receive via. When receiving the request signal and the index signal in this way, the receiving circuit 13 generates a received signal and outputs the received signal to the microcomputer 14.

  The microcomputer 14 is a CPU unit including a CPU, a ROM, a RAM, and the like (not shown), and includes a memory 14a. In the memory 14a, an ID code individually set for each portable device 2 is stored. The microcomputer 14 responds to the request signal when the reception signal is input from the reception circuit 13 based on the transmission of the request signal and the index signal from the door unlock control device 3 as described above. Then, an ID code signal including the ID code of the portable device 2 is generated, and the ID code signal is output to the transmission circuit 15.

  The transmission circuit 15 is for transmitting the ID code signal input from the microcomputer 14. When the driver wearing the portable device 2 touches the door outside handle 21, the transmission circuit 15 of the present embodiment transmits an ID code signal via the communication electrode 12 and the driver's human body.

  The door unlock control device 3 includes a door outside handle 21, a transmission circuit 22, a reception circuit 23, and a microcomputer 24. The door outside handle 21 is operated to open the in-vehicle door from the outside of the vehicle. The communication electrode 21 a is exposed on the surface of the door outside handle 21.

  The transmission circuit 22 is for transmitting a request signal and an index signal input from the microcomputer 24. When the driver wearing the portable device 2 touches the door outside handle 21, the transmission circuit 22 of the present embodiment transmits a request signal and an index signal from the microcomputer 24 via the communication electrode 21a and the driver's human body. To do.

  The receiving circuit 23 is for receiving an ID code signal transmitted from the portable device 2 in response to the request signal. When the driver wearing the portable device 2 touches the door outside handle 21, the receiving circuit 23 of the present embodiment receives an ID code signal from the portable device 2 via the driver's human body and the communication electrode 21a. . When receiving the ID code signal in this way, the receiving circuit 23 generates a received signal and outputs the received signal to the microcomputer 24.

  The microcomputer 24 is a CPU unit including a CPU, a ROM, a RAM, and the like (not shown), and includes a memory 24a. In this memory 24a, the same ID code (vehicle-side ID code) as the ID code of the corresponding portable device 2 is stored. Then, the microcomputer 24 outputs a request signal to the transmission circuit 22 in order to establish bidirectional communication with the portable device 2. The microcomputer 24 generates an index signal described later, adds the index signal to the request signal, and outputs the request signal to the transmission circuit 22. The microcomputer 24 according to the present embodiment outputs a request signal and an index signal to the transmission circuit 22 when a driver wearing the portable device 2 touches the door outside handle 21 as a trigger.

  When the reception signal is input from the reception circuit 23 based on the output of the request signal and the index signal, the microcomputer 24 receives the ID code of the portable device 2 included in the reception signal, the memory It is determined whether or not the vehicle-side ID code stored in 24a matches. That is, in this case, the microcomputer 24 performs ID code verification. Then, the microcomputer 24 outputs a door unlock permission signal to the door ECU 30 on the condition that both ID codes are matched by the ID code collation.

When the door unlock permission signal is thus input from the microcomputer 24, the door ECU 30 unlocks the vehicle-mounted door by controlling an actuator (not shown).
Next, the operation in the case of unlocking the vehicle-mounted door will be described using the conceptual diagram of in-vivo communication shown in FIG.

  When the driver wearing the portable device 2 touches the door outside handle 21, a request signal and an index signal are transmitted from the door unlock control device 3 via the driver's human body. When the request signal and the index signal are received by the portable device 2, an ID code signal is transmitted from the portable device 2 via the driver's human body.

  When this ID code signal is received by the door unlock control device 3, the door unlock control device 3 collates the ID code, and the ID code of the portable device 2 matches the ID code on the car side. The vehicle door is unlocked on condition of

Next, an index signal generated by the microcomputer 24 of the door unlock control device 3 will be described with reference to FIG.
This index signal is a signal that serves as an index when the voltage level of the ID code signal transmitted from the portable device 2 in response to the request signal from the door unlock control device 3 is determined on the portable device 2 side. .

  As shown in FIG. 3, the microcomputer 24 generates a plurality of index signals having different voltage levels. Here, the first index signal is constituted by the first pulse signal P1 having the highest voltage level. The voltage level of the first pulse signal P1 is set to V1. On the other hand, the second index signal is constituted by the second pulse signal P2 having the second highest voltage level. The voltage level of the second pulse signal P2 is set to V2. On the other hand, the third index signal is constituted by the third pulse signal P3 having the third highest voltage level. The voltage level of the third pulse signal P3 is set to V3. Similarly, the Nth index signal is constituted by the Nth pulse signal PN having the Nth highest voltage level, that is, the Nth pulse signal PN having the lowest voltage level. The voltage level of the Nth pulse signal PN is set to VN.

  V1 to VN have a magnitude relationship of V1> V2> V3>. Further, the voltage level difference between adjacent index signals is set to be equal to each other. Incidentally, the voltage level of the request signal is set to V1 like the voltage level of the first pulse signal P1.

  Then, the microcomputer 24 adds the first to Nth index signals to the request signal. That is, the microcomputer 24 adds the first index signal to the Nth index signal to the request signal in descending order of voltage level. Specifically, the microcomputer 24 sequentially adds the request signal in the order of the first pulse signal P1, the second pulse signal P2, the third pulse signal P3,..., And the Nth pulse signal PN.

  Then, the microcomputer 24 outputs a request signal to which the index signal is added to the transmission circuit 22 as a trigger when the driver wearing the portable device 2 touches the door outside handle 21 as a trigger. As a result, in a state where the driver wearing the portable device 2 is touching the door outside handle 21, the request signal to which the index signal is added is transmitted from the transmission circuit 22.

Next, an ID code signal generated by the microcomputer 14 of the portable device 2 will be described with reference to FIGS.
As described above, when the request signal to which the plurality of index signals shown in FIG. 3 are added is transmitted from the door unlock control device 3, the reception signal is input from the reception circuit 13 to the microcomputer 14. Here, even if the transmission signal from the door unlock control device 3 is fixed to the one shown in FIG. 3, the reception signal input from the reception circuit 13 to the microcomputer 14 differs depending on the quality of the communication environment. . In other words, the reception circuit 13 can receive even an index signal having a lower voltage level in an environment with a better communication state. On the other hand, the reception circuit 13 can receive only an index signal having a higher voltage level in an environment where the communication state is poor.

  In the present embodiment, the reception signal shown in FIG. 4A is input from the reception circuit 13 to the microcomputer 14. That is, in the present embodiment, the request signal and the first to third index signals are received by the receiving circuit 13, while the index signals after the fourth index signal are not received by the receiving circuit 13. .

  Here, the first reception signal R1 shown in FIG. 4A is the reception signal of the first pulse signal P1 shown in FIG. The voltage level of the first reception signal R1 is substantially maintained at V1, which is the voltage level of the first pulse signal P1. On the other hand, the second received signal R2 is a received signal of the second pulse signal P2. The voltage level of the second reception signal R2 is substantially maintained at V2, which is the voltage level of the second pulse signal P2. On the other hand, the third reception signal R3 is a reception signal of the third pulse signal P3. The voltage level of the third reception signal R3 is substantially maintained at V3 that is the voltage level of the third pulse signal P3.

  When the reception signal is input from the reception circuit 13 to the microcomputer 14 in this way, the microcomputer 14 selects the reception signal having the second lowest voltage level from the reception signals, and the voltage level of the selected reception signal. Is determined as a voltage level when transmitting the ID code signal. In other words, the microcomputer 14 selects an index signal having the second lowest voltage level from among the plurality of index signals received by the receiving circuit 13, and transmits an ID code signal indicating the voltage level of the selected index signal. Determine if the voltage level. In other words, the microcomputer 14 determines the voltage level when transmitting the ID code signal, using as an index a plurality of index signals with different voltage levels transmitted in addition to the request signal. In the present embodiment, the second received signal R2, in other words, the second indicator signal is selected, and the voltage level of the selected second indicator signal is determined as the voltage level when the ID code signal is transmitted. Is done.

  Then, the microcomputer 14 generates an ID code signal having the voltage level determined as described above, and outputs the ID code signal to the transmission circuit 15. In the present embodiment, as shown in FIG. 4B, an ID code signal having a voltage level of the second reception signal R <b> 2 is generated by the microcomputer 14, and the ID code signal is output to the transmission circuit 15.

As a result, the ID code signal is transmitted from the transmission circuit 15 in a state where the driver wearing the portable device 2 is touching the door outside handle 21.
As described above, according to the present embodiment, the following operations and effects can be obtained.

  (1) When two-way communication is performed between the door unlock control device 3 and the portable device 2, the microcomputer 24 of the door unlock control device 3 generates a plurality of index signals having different voltage levels. . Then, the plurality of indicator signals generated by the microcomputer 24 are added to the request signal and transmitted by the transmission circuit 22 of the door unlock control device 3.

  Then, the ID codes individually set for each portable device 2 by the microcomputer 14 of the portable device 2 using the plurality of indicator signals having different voltage levels transmitted as a result of being added to the request signal in this way. The voltage level when transmitting the ID code signal including is determined. Then, the microcomputer 14 generates the ID code signal having the determined voltage level. Then, the ID code signal generated by the microcomputer 14 is transmitted by the transmission circuit 15 of the portable device 2.

  Here, regardless of whether the communication environment is good or bad, the voltage level of the transmission signal from the portable device 2 is not fixed, but the voltage level is determined using the plurality of indicator signals as indicators. For this reason, it becomes possible to arbitrarily set the voltage level according to the quality of the communication environment. Therefore, it is possible to perform suitable communication in accordance with the communication environment.

  (2) The index signal having the second lowest voltage level is selected from the plurality of index signals received by the receiving circuit 13 by the microcomputer 14 of the portable device 2, and the voltage level of the selected index signal is the ID code. The voltage level when a signal is transmitted is determined. For this reason, compared with the structure fixed to the thing with the highest voltage level irrespective of the quality of communication environment, consumption of the battery power of the portable device 2 can be suppressed.

  (3) The index signal having the lowest voltage level is not selected, but the index signal having the second lowest voltage level is selected. For this reason, there is a high possibility that the ID code signal transmitted from the portable device 2 is reliably received on the door unlock control device 3 side. Therefore, suitable communication can be performed while suppressing the battery power consumption of the portable device 2.

  (4) The in-vehicle door is unlocked as a result of the human body communication using the driver's human body as a signal transmission path triggered by the driver wearing the portable device 2 touching the door outside handle 21. . In other words, since the operation essential for getting on is actively utilized, the driver is not forced to perform any special operation, and there is no room for confusion for the driver. Since the operability is considered in this way, the smart key system 1 excellent in convenience can be provided.

  (5) The portable device 2 has a wristwatch shape, and the reference potential electrode 11 and the communication electrode 12 are exposed on the back surface of the portable device 2. For this reason, when such a portable device 2 is mounted so as to surround the driver's arm, the reference potential electrode 11 and the communication electrode 12 are in close contact with the driver's arm. Therefore, human body communication using the driver's human body as a signal transmission path can be suitably performed.

In addition, the said embodiment can also be changed and actualized as follows.
-The microcomputer 14 of the portable device 2 selects the index signal having the lowest voltage level from among the plurality of index signals received by the receiving circuit 13, and the ID code signal is transmitted with the voltage level of the selected index signal. In this case, the voltage level may be determined. If comprised in this way, consumption of the battery power of the portable device 2 can be suppressed further.

  The microcomputer 14 of the portable device 2 selects an index signal whose voltage level is the third or lower from among the plurality of index signals received by the receiving circuit 13, and the voltage level of the selected index signal is the ID code signal It is good also as a structure determined by the voltage level in the case of transmitting. If comprised in this way, more suitable communication can be performed, suppressing consumption of the battery power of the portable device 2.

  A configuration in which an index signal having the lowest voltage level is selected when a predetermined number (for example, 5) of index signals is received, a configuration in which the second lowest index signal is selected, and a third and subsequent lower index signals are selected. Any of the configurations may be adopted.

A configuration may be adopted in which a plurality of index signals are added to the request signal in order of increasing voltage level and transmitted from the transmission circuit 22.
A configuration may be adopted in which a plurality of indicator signals are added prior to the request signal and transmitted from the transmission circuit 22.

  The portable device 2 is not limited to a wristwatch type, and may be a bracelet type, a glasses type, a ring type, or the like. In short, the portable device 2 only needs to be in contact with the driver's human body, and is preferably in close contact with the driver's human body. More preferably, it is to be mounted.

The smart key system 1 is not limited to intra-body communication, but may be wired communication or wireless communication.
-It may be embodied in a smart key system having a smart ignition function instead of or in addition to the smart entry function. Here, the smart ignition function is a function that permits starting of the engine when a corresponding smart key is brought into the vehicle. When the engine start switch (for example, a rotary switch or a push switch) is operated in such a state where the engine is permitted to start, the engine is started. In this case, the same type of communication electrode as the communication electrode 21a is exposed on the surface of the engine start switch.

The block diagram which shows the structure of a smart key system. Conceptual diagram of human body communication. The wave form diagram which shows the parameter | index signal produced | generated by the microcomputer of a door unlock control apparatus. (A) The wave form diagram which shows the received signal input into the microcomputer from the receiving circuit of a portable device.

            (B) Waveform diagram showing an ID code signal generated by a microcomputer of the portable device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Smart key system as a communication system, 2 ... Portable machine, 3 ... Door unlock control apparatus as a communication apparatus, 13 ... Reception circuit as a receiving means, 14 ... Microcomputer as a determination means and a 2nd generation means, 15 ... Transmission circuit as second transmission means, 22 ... Transmission circuit as first transmission means, 24 ... Microcomputer as first generation means.

Claims (5)

In a communication apparatus comprising first transmission means for transmitting a request signal in order to establish bidirectional communication with a portable device,
First generation means for generating a plurality of indicator signals having different voltage levels as indicators when a voltage level of a signal transmitted from the portable device in response to the request signal is determined on the portable device side;
The first transmission unit transmits the plurality of index signals generated by the first generation unit by adding to the request signal. In a portable device comprising a second transmission means for transmitting an ID code signal including an ID code individually set for each portable device in response to a request signal transmitted from a communication device,
Determining means for determining a voltage level when transmitting the ID code signal, using as an index a plurality of index signals having different voltage levels transmitted in addition to the request signal;
Second generation means for generating the ID code signal of the voltage level determined by the determination means,
The portable device characterized in that the second transmission means transmits the ID code signal generated by the second generation means. The portable device according to claim 2, wherein
Receiving means for receiving the plurality of indicator signals;
The determining unit selects an index signal having the lowest voltage level from among the plurality of index signals received by the receiving unit, and the voltage level when the ID code signal is transmitted as the voltage level of the selected index signal. A portable device characterized by being determined. The portable device according to claim 2, wherein
Receiving means for receiving the plurality of indicator signals;
The determining unit selects an index signal having the second lowest voltage level from among the plurality of index signals received by the receiving unit, and transmits the ID code signal based on the voltage level of the selected index signal. A portable device characterized by determining a voltage level. A communication system comprising the communication device according to claim 1 and the portable device according to any one of claims 2 to 4.

Images