WO2007010970A1 - Communication system and communication apparatus - Google Patents

Abstract

A communication system comprises a vehicle; a first transceiver; a first exciter that is connected to the first transceiver and that excites, based on a first signal transmitted from the first transceiver, a conductor of the vehicle, receives a second signal transmitted from the conductor of the vehicle and transmits the received second signal to the first transceiver; a second transceiver disposed in the vehicle; a second exciter that is connected to the second transceiver and that excites, based on the second signal transmitted from the second transceiver, the conductor of the vehicle via a cable, receives the first signal transmitted from the conductor of the vehicle and transmits the received first signal to the second transceiver; a hole through which the cable is put into the vehicle; and a high frequency noise inhibiting element that covers the cable at the hole.

Description

 Specification

 Communication system and communication apparatus

 Technical field

 The present invention relates to a communication system and a communication device. In particular, the present invention relates to a communication system and a communication device inside a vehicle including, but not limited to, a moving body such as an automobile, a truck, a train, a ship, and an aircraft.

 Background art

 Conventionally, information communication within vehicles such as automobiles, trucks, trains, ships, and aircraft has been performed by arranging conductive wires between points for information communication. Recently, optical cables have played this role as well. Conventional wireless technology in the 2.4 GHz frequency band has also been used.

 [0003] For example, wireless communication is used for information communication in a system for monitoring the air pressure of an automobile tire. FIG. 16 shows an information communication system using a 2.4 GHz frequency band in a car using conventional wireless technology. 100a is an automobile body frame, and 100b is an automobile cabin. 101a, 101b, 101c and lOld are tires, and a wheel part (not shown) of each tire has a sensor 105a and a transmitter 104a, a sensor 105b and a transmitter 104b, a sensor 105c and a transmitter 104c, and a sensor. 1 05d and transmitter 104d are provided. The sensor 105a is an air pressure sensor that senses the air pressure of the tire 101a, and transmits information (air pressure information) based on the air pressure of the tire 101a to the transmitter 104a. Similarly to the sensor 105a, the sensors 105b, 105c, and 105d transmit signals based on the air pressure of the timers 101b, 101c, and lOld to the transmitters 104b, 104c, and 104d, respectively.

[0004] Transmitters 104a, 104b, 104c, and 104d transmit air pressure information of tires 101b, 101c, and lOld using radio waves in the 2.4 GHz frequency band, respectively. The receivers 103a, 103b, 103c and 103d receive the air pressure information to which the transmitters 104a, 104b, 104c and 104d are also transmitted and transmit them to the CPU 102. The CPU 102 processes the air pressure information and determines whether the air pressure of each tire 101a, 101b, 101c and lOld is at an appropriate value. Then, information based on the result is transmitted to the display device 106. The display device 106 displays the information that the CPU power is also transmitted, and the driver of the car looks at the information on the display device 106 to determine whether the air pressure of the tires 101a, 101b, 101c, and 101d is at an appropriate value. Can be obtained.

 Patent Document 1: US Pat.No. 6,600,896

 Disclosure of the invention

 Problems to be solved by the invention

 In the in-vehicle communication using the conventional radio technology in the 2.4 GHz frequency band as shown in FIG. 16, the transmitters 104a, 104b, The structure of 104c and 104d and the receivers 103a, 103b, 103c and 103d is complicated, and the power consumption of the transmitter is large because the output level of the transmitter is set high in order to increase the success rate of data transmission. There is a problem.

 [0006] In view of such problems in the conventional wireless communication technology, the present applicant has proposed an epoch-making information communication system inside or very close to a vehicle (see Patent Document 1).

 [0007] This epoch-making information communication system by the present applicant is an information communication system between a first location inside a vehicle and a second location inside or near the vehicle. The vehicle has a conductive metal structure that defines one or more major compartments such as bonnets, cabins, and trunks. In this communication system, it is electrically connected to the first communication device and the metal structure of the vehicle! An excitation device (exciter device) is provided that includes an exciting exciter. Each exciter includes an exciter conductively connected to the communication device and the metal structure of the vehicle. Each communication device receives information at each location, modulates the signal accordingly, and performs two-way communication at radio frequencies. The exciter receives signals from the respective communication devices and conductively injects the signals as currents into the vehicle's metal structure. Each exciter also conductively restores current from the vehicle's metal structure, obtains a signal from the current, and provides the signal to each communication device. The communication device then demodulates the signal strength information and provides the information at each location.

[0008] This epoch-making information communication system by the present applicant is based on the body of a vehicle such as an automobile (conduction The signal excited by the exciter is injected into the metal structure), the signal is taken into the cabin (cabin), received by the receiver installed near the driver's seat, and the received signal is processed by the CPU. The display device is configured to display.

 [0009] When this information communication system of the present applicant is adopted in a tire pressure monitoring system for automobiles, the following system is configured.

 [0010] First, an exciter is provided in the wheel part of an automobile, and tire pressure information is injected into the wheel part via the exciter by a signal generator force of about 35 MHz.

 [0011] A signal injected into the wheel is injected into the body of the automobile via the axle, and a high-frequency current flows from the wheel to the body. When this high-frequency current flows, electromagnetic waves are generated. A large amount of this electromagnetic wave is generated on the outer surface of the automobile body due to the skin effect.

 [0012] The electromagnetic wave generated in the body is drawn into the cabin as a received signal. One end of the coaxial cable is connected to the outer surface of the body, and the received signal is received by the receiver by pulling it into the car through a coaxial cable through a hole of about 1 cm in the body and connecting it to the receiver. The Connect one end of the coaxial cable to the outer surface of the body by soldering or screwing. The receiver receives the signal injected into the wheel and displays tire pressure information on the display.

 [0013] By using such a system, it is possible to perform information communication in the vehicle with a simple configuration and high efficiency without using conventional wire communication or conventional wireless communication using a lead wire or optical cable.

 [0014] Recently, in in-vehicle information communication, it has been required to transmit a large amount of information with low power consumption at a high transmission rate. For this reason, even in the ground-breaking information communication system by the present applicant, there is a demand for a technique for improving the transmission efficiency and further improving the transmission speed.

 Therefore, the present invention has been made to solve the above-described problems, and provides a communication system in a vehicle that can realize low power consumption, high efficiency, and high speed transmission.

 Means for solving the problem

[0016] According to the present invention, a vehicle, a first transceiver, and the first transceiver are connected, Based on the first signal transmitted from the first transceiver, the electrical conductor of the vehicle is excited, and the second signal transmitted from the electrical conductor of the vehicle is received, and the first transceiver A first exciter for transmission, a second transmitter / receiver installed inside the vehicle, and the second signal connected to the second transmitter / receiver and transmitted by the second transmitter / receiver. A second exciter for exciting the conductor of the vehicle through a cable and receiving the first signal transmitted to the conductor force of the vehicle and transmitting the first signal to the second transceiver There is provided a communication system having a hole for introducing the cable into the vehicle, and a high-frequency noise prevention element covering the cable in the hole.

 [0017] The high-frequency noise prevention element may be a ferrite core or a toroidal core.

 [0018] Further, according to the present invention, the vehicle, the first transceiver, and the first transceiver connected to the first transceiver, the first transceiver is transmitted based on the first signal transmitted. A first exciter that excites a conductor and receives a second signal transmitted from the conductor of the vehicle and transmits the second signal to the first transceiver; and a first exciter installed in the vehicle. And the second transmitter / receiver, and based on the second signal transmitted from the second transmitter / receiver, excites the electric conductor of the vehicle through a semi-rigid cable. A second exciter for receiving the first signal transmitted from the conductor of the vehicle and transmitting the first signal to the second transmitter / receiver, and for introducing the semi-rigid cable into the vehicle. A hole and an insulator covering the cable in the hole. Shin system is provided.

 In addition, a sensor may be connected to the first transceiver.

[0020] In addition, a CPU may be connected to the second transceiver.

[0021] According to the present invention, the first transceiver is connected to the first transceiver, and the vehicle conductor is excited based on the first signal transmitted from the first transceiver. A first exciter that receives the second signal transmitted from the vehicle and transmits the signal to the first transceiver, and a second transceiver installed in the vehicle. Based on the second signal connected to the second transmitter / receiver and transmitted from the second transmitter / receiver. A second exciter that excites the conductor of the vehicle through a cable and receives the first signal transmitted from the conductor of the vehicle and transmits the first signal to the second transceiver; and There is provided a communication apparatus having a hole for introducing a cable into the vehicle and a high-frequency noise preventing element that covers the cable in the hole.

[0022] The high-frequency noise prevention element may be a ferrite core or a toroidal core.

[0023] According to the present invention, the first transceiver is connected to the first transceiver, and the vehicle conductor is excited based on the first signal transmitted from the first transceiver. A first exciter that receives the second signal transmitted from the vehicle and transmits the signal to the first transceiver, and a second transceiver installed in the vehicle. The conductor of the vehicle is excited through a semi-rigid cable based on the second signal connected to the second transmitter / receiver and transmitted from the second transmitter / receiver. A second exciter that receives the first signal transmitted from the body and transmits the first signal to the second transceiver; a hole for introducing the semi-rigid cable into the vehicle; and the hole! And an insulator covering the cable.

[0024] A sensor may be connected to the first transceiver.

[0025] In addition, a CPU may be connected to the second transceiver.

 The invention's effect

 [0026] According to the communication system and the communication device of the present invention, it is possible to perform information communication in a vehicle with a simple configuration and high efficiency without using a conventional wire communication or a conventional wireless communication using an optical cable or an optical cable. There is a remarkable effect.

 Brief Description of Drawings

 FIG. 1 is a schematic configuration diagram of an embodiment of a communication system according to the present invention.

 FIG. 2 is a schematic configuration diagram of an embodiment of a communication system according to the present invention.

 FIG. 3 is a simplified cross-sectional view of an automobile according to an embodiment of a communication system of the present invention.

 FIG. 4 is a diagram of a portion where the cable 19 is drawn into the cabin 10b in the embodiment of the communication system of the present invention.

FIG. 5 is a block diagram of an embodiment of a communication system of the present invention. FIG. 6 is a diagram showing a configuration of an exciter of the communication system of the present invention according to the present embodiment.

 FIG. 7 is a graph showing frequency characteristics of the exciter shown in FIG. 6 (b).

 FIG. 8 is a graph showing the S parameter characteristics of the exciter shown in FIG. 6 (b).

 FIG. 9 is a schematic configuration diagram of an embodiment of a communication system according to the present invention.

 FIG. 10 is a cross-sectional view and a side view of a semi-rigid wire 40 used in the communication system of the present invention.

 FIG. 11 is a side view of a toroidal core 50 used in the communication system of the present invention.

 FIG. 12 is a measurement screen of a network analyzer that measures S-parameter S21 characteristics of an exciter used in the communication system of the present invention.

 FIG. 13 is an example of a communication system of the present invention.

 FIG. 14 is a graph showing transmission characteristics according to an embodiment of the communication system of the present invention.

 FIG. 15 is an example of a communication system according to the present invention.

 FIG. 16 is a schematic configuration diagram of an information communication system using a frequency band of 2.4 GHz by a conventional wireless technology in an automobile.

 Explanation of symbols

 [0028] 10a body 10b cabin 10c body frame l la, l ib, l lc, l id tire, wheel 12 CPU 14a, 14b, 14c, 14d transceiver 15a, 15b, 15c, 15d sensor 16a, 16b, 16c, 16d Exciter 17 Transceiver 18 Exciter 1 9 Cable 20 Ferrite core 21 Display 31 hole

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0029] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be carried out in many different modes and should not be construed as being limited to the description of the embodiments described below. Note that in the drawings referred to in this embodiment mode and Examples 1 to 3, the same portions or portions having similar functions are denoted by the same reference numerals, and repeated description thereof is omitted.

[0030] Reference is made to FIG. FIG. 1 (a) is a schematic configuration diagram of a communication system of the present invention according to the present embodiment. In the present embodiment, an example in which the communication system of the present invention is used in an automobile tire pressure monitoring system is shown. 10a is the body of the car, 10b is the cabin, and 10c is the axle of the body. The car body 10a and cabin 10b are electrically connected Yes. The wheels l la, l lb, 11c and l id which are electrically connected to the axle part of the body have exciters 16a, 16b, 16c and 16d (in FIG. 1, 16a and 16b are not shown). ) Connected to the transceivers 15a, 15b, 15c and 15d (in FIG. 1, 15a and 15b are not shown). In the present embodiment, for convenience of explanation, the tire and the wheel are collectively shown as tire · wheel l la, l ib, 11c and l id. In the present embodiment, the body 10a and the axle portion 10c of the body are electrically connected, and these may be collectively referred to as the body 10a.

[0031] Fig. 1 (b) shows a cross-sectional view along AA 'of the tire / wheel 11c and the body (axle portion) shown in Fig. 1 (a). It is understood that the wheel portion of the tire 'wheel 11c is electrically connected to the body (axle) 10c. 22c is a wheel cover.

 FIG. 2 shows a schematic configuration diagram of a communication system of the present invention according to the present embodiment. 11a, 11b, 11c, and id are tire'wheels, and sensors 15a, 15b, 15c, and 15d are provided on the respective wheel portions. The sensor 15a is an air pressure sensor that senses the air pressure of the tire wheel 11a, and transmits a signal (air pressure signal) to the transceiver 14a based on the air pressure of the tire wheel 1la. Similarly to the sensor 15a, the sensors 15b, 15c, and 15d transmit the pneumatic signals of the tires' wheels l lb, 11c, and l id to the transceivers 14b, 14c, and 14d, respectively. In the present embodiment, the frequency of the pneumatic signal transmitted from the transceivers 14a to 14d is about 20 MHz, but is not limited to this. The frequency band used for the communication system of the present invention is preferably 0.5 MHz or more, and more preferably 20 MHz to 25 MHz. As shown in FIG. 12, this preferred frequency band is 20 MHz to 25 MHz and has a small transmission loss when the S parameter S21 characteristic is measured by the network analyzer of the exciter of this embodiment! / It is understood from that.

[0033] In the present embodiment, an example in which the communication system of the present invention is used in a tire air pressure monitoring system is described. Therefore, the force using the sensors 15a, 15b, 15c and 15d. The communication system uses a light control system that controls light ON and OFF, light intensity, etc., an air conditioner control system, and a source such as a DVD. When used in an image information control system, a switch element, relay element or the like may be used instead of a sensor.

 [0034] The transceiver 14a inputs a pneumatic signal to the exciter 16a, and the pneumatic signal is excited by the exciter 16a and injected into the axle portion 10c of the body. A high-frequency current flows through the body frame 10c due to the excited air pressure signal. Similar operations are performed for the transceivers 14b, 14c, and 14d. In addition, header information is attached to each air pressure signal generated by each of the transceivers 14a, 14b, 14c, and 14d, and each information is identified. The frequency of each pneumatic signal generated by each transceiver 14a, 14b, 14c and 14d may be changed, or the time division method may be used!

 FIG. 3 is a simplified cross-sectional view of an automobile used in the communication system of the present invention according to this embodiment. The tire pressure signals excited by the exciters 16a, 16b, 16c, and 16d are respectively injected into the body axle section 10c, and the body axle section 10c to the body 10a have high-frequency signals based on the respective pneumatic signals. Current flows. As shown in Fig. 3, many electromagnetic waves are generated on the outer surface of the body 10a due to the skin effect.

[0036] Reference is now made to FIG. FIG. 4 (a) shows a view of the portion where the cable 19 is pulled into the cabin 10b, and FIG. 4 (b) shows a cross-sectional view of FIG. 4 (a). A cable 19 (in this embodiment, a coaxial cable) is electrically connected to a part of the body 10a, and electromagnetic waves generated on the outer surface of the body are drawn into the cabin 1 Ob using the cable 19. In the present embodiment, a force that electrically connects the cable 19 to a part of the body 10a by using the solder bump 34 may be screwed or other means that are not limited to this. As shown in FIG. 4 (a), a hole 31 having a diameter of about 1 cm is formed in an iron plate (in this embodiment, a trunk plate 30) that is a part of the body 10a, and a magnetized ferrite core 20 is formed in the hole 31. The cable 19 is taken into the vehicle so that the cable 19 is covered with the ferrite core 20. The size of the hole 31 can be changed in time. Since the electromagnetic wave generated on the outer surface of the body 10a flows to the ferrite core 20, the signal transmitted to the cable 19 is not adversely affected by the electromagnetic wave generated on the outer surface of the body 10a. Therefore, electromagnetic waves generated on the outer surface of the body 10a can be taken into the cabin 10b. [0037] Referring again to FIG. The electromagnetic wave taken into the cabin 10b by the cable 19 is transmitted to an exciter 18 electrically connected to the cable 19, and the air pressure of each tire wheel l la, l ib, 11c and l id is transmitted by the exciter 18 The signal is restored. The restored air pressure signal is transmitted to the transceiver 17 and received. The air pressure signal received by the transceiver 17 is transmitted to the CPU 12, processed by the CPU 12, and then transmitted to the display device 21. The display device 21 displays the air pressure of each tire wheel l la, l lb, 11c and l id processed by the CPU 12. The driver of the automobile can obtain information on whether or not the air pressure of the tires 101a, 101b, 101c and 101d is an appropriate value by looking at the information on the display device 106.

 In addition, the CPU 12 transmits / receives a request signal for a pneumatic signal and other control signals to the transceiver 17 by the transceivers 14a, 14b, 14c, and 14d. The signal is excited by the exciter 16 a and injected into the cable 19. Since the cable 19 is covered with the ferrite core 20 that is a high-frequency noise prevention element, the electromagnetic wave generated on the outer surface of the body 10a flows to the ferrite core 20 and thereby the electromagnetic wave generated on the outer surface of the body 10a. The signal transmitted to table 19 is not adversely affected. Therefore, the signal transmitted to the cable 19 can be transmitted to the trunk plate 30 which is a part of the body 10a, and a high-frequency current flows on the outer surface of the body 10a due to the skin effect. The high-frequency current flowing on the outer surface of the body 10a flows to the axle portion 10c of the electrically connected body, and the signals are restored by the exciters 16a, 16b, 16c and 16d, and the transceivers 14a, 14b, 14c and Those signals are transmitted to 14d.

 [0039] As described above, bidirectional communication is performed between the transceivers 14a, 14b, 14c and 14d and the transceiver 17, in other words, between the sensors 15a, 15b, 15c and 15d and the CPU. be able to. By using such a system, it is possible to perform information communication in the vehicle with a simple configuration and high efficiency without using a conventional wire communication using a conducting wire or an optical cable or a conventional wireless communication.

[0040] Reference is now made to FIG. FIG. 5 is a block diagram showing the communication system of the present invention according to this embodiment. In this embodiment, the sensor 15a uses a power solar cell provided with a notch (250 mAH, 1.8V), or self-power generation using a coil. A battery or the like may be used. Further, since the temperature of the tire 'wheel 11 _a is about 100 ° C, the electromotive force generated using a thermocouple, may be used as an alternative to a battery.

[0041] In the present embodiment, the transceiver 14a includes the CPU 14a-1, TXZRX (transmission / reception) IC 14a-2, IF / BPF (interface / bandpass filter) 14a-3, OSC (oscillator) 14a— 4S and BPF (bandpass filter) 14a-5 1S are not limited to this. In addition, transceiver 17 consists of CPU17-1, TX / RX (transmission / reception) IC17-2, IFZBPF (interface Z bandpass filter) 17-3, OSC (oscillator) 17-4 and BPF (bandpass filter) 17-5 However, the present invention is not limited to this.

 Next, refer to FIG. FIG. 6 shows an example of the exciters 16a, 16b, 16c and 16d and 18 of the communication system of the present invention according to the present embodiment. The exciter shown in Fig. 6 (a) consists of a resistor R and a capacitor CO connected in series. Although the values of the resistor R and the capacitor CO can be changed in a timely manner, according to the results of experiments by the present inventors, it is preferable that R = 51 Ω and CO = 0.1 F are preferable. In the present embodiment, the force connecting the resistor R side terminal to the transceiver side and the capacitor CO side terminal to the body axle 10c side is not limited to this.

FIG. 6 (b) shows another example of the exciters 16a, 16b, 16c and 16d and 18 of the communication system of the present invention according to the present embodiment. The exciter shown in Fig. 6 (b) has five capacitors C1 to C5 and two inductors L2 and L4. The exciter shown in Fig. 6 (b) is a kind of low-pass filter. As shown in Figure 6 (b), this exciter consists of a circuit A in which an inductor L2 and a capacitor C2 are connected in parallel and a circuit B in which an inductor L4 and a capacitor C4 are connected in parallel. One end of capacitors Cl, C3, and C5 is connected to each end of A and B, and the other end of capacitors Cl, C3, and C5 is connected to have a common potential. As shown in Fig. 6 (b), in this exciter, the end of capacitor C1 is `` port 1 '', the end of capacitor C5 is port 2, and the characteristic impedance of port 1 is Zin (input impedance ), The characteristic impedance of port 2 is Zout (output impedance). In the present embodiment, the cut-off frequency is fc, Zin = Zout, and the design values of the capacitors C1 to C5 and the inductors L2 and L4 are obtained using the following formulas (1) to (3). Note that FSF is a frequency scaling factor. FSF = 2 π -fc (1)

C = Cn / (FSF-Zin) (2) L = (L

 n-Zin) / FSF (3)

 [0045] The exciter shown in FIG. 6 (b) has the frequency characteristics shown in FIG. Here, the following equations (4) and (5) are established for the frequencies Ω2 and Ω4. Amin is the maximum attenuation. Q2 = 3fc'L2ZC2 (4) Q4 = 2fc-L4 / C4

 In this embodiment, the input / output impedance is set to Zin = Zout = 50Q, and the cutoff frequency fc is changed from 3.5 to 100 MHz so as to have a valley of attenuation at the frequency of Ω2 and the frequency of Ω4, When the design values of capacitors C1 to C5 and inductors L2 and L4 were determined, the results shown in Table 1 and Table 2 below were obtained.

 [0047] [Table 1]

 [0048] [Table 2]

[0049] As shown in Table 1 and Table 2, even when the cut-off frequency fc is changed in a timely manner, Matching with the connection destination of the exciter (transmitter / receiver, axle part of the body) by appropriately selecting the values of the capacitors C1 to C5 and the inductors L2 and L4 (input / output impedances Zin and Zout are connected to It can be seen that the impedance can be the same as

 [0050] Reference is now made to Table 3. Table 3 shows the frequency-dependent characteristics of the scattering parameters (S-parameters) of the exciter shown in Fig. 6 (b). For this frequency dependence, the device constants of fc = 45MHz in Table 2 (C1 = 75PF, C2 = 5.5 PF, C3 = 110PF, C4 = 15PF, C5 = 70PF, L2 = 0.26 H, L4 = 0.21) were used. Is.

[0051] [Table 3]

FIG. 7 is a graph showing the frequency dependence of the S parameter shown in Table 3. In Fig. 7, “♦” indicates S-parameter S21 (forward impedance characteristics), “Country” indicates S-parameter S11 (input-side impedance characteristics), and “△” indicates S-parameter S22 (output-side impedance characteristics). Yes.

[0053] As described above, between the transceivers 14a, 14b, 14c and 14d and the transceiver 17, In other words, bidirectional communication can be performed between the sensors 15a, 15b, 15c and 15d and the CPU. By using such a system, it is possible to perform information communication in the vehicle with a simple configuration and high efficiency without using a conventional wire communication using a conducting wire or an optical cable or a conventional wireless communication.

 Example 1

 In the present embodiment, another example of the communication system of the present invention will be described.

[0055] Reference is made to FIG. FIG. 9 shows a schematic configuration diagram of a communication system of the present invention according to the present embodiment. The communication system of the present invention according to the present embodiment is provided with transmitters / receivers 17a and 18a corresponding to the transmitter / receiver 14a and the exciter 16a. Similarly, transmission / reception is performed corresponding to the transmitter / receiver 14b and the exciter 16b. 17b and 18b are provided, transceivers 17c and 18c are provided corresponding to the transceiver 14c and the exciter 16c, and transceivers 17d and 18d are provided corresponding to the transceiver 14d and the exciter 16d. It has been.

[0056] By adopting the configuration as in the present embodiment and changing the frequency of the signal from each transceiver, it is possible to perform communication between each elementary receiver without adding information such as a header. Example 2

 [0057] In the above-described embodiment, the example in which the ferrite core 20 is used as the high-frequency noise preventing element that covers the periphery of the cable described in the above-described embodiment has been described. However, in this embodiment, the ferrite core is used as the ferrite core. Instead, an example of the communication system of the present invention using a semi-rigid wire or a toroidal core will be described. Since other configurations are the same as those in the above-described embodiment, description thereof is omitted here.

 [0058] Reference is made to FIG. FIGS. 10 (a) and 10 (b) show a cross-sectional view and a side view of the semi-rigid wire 40 used in the communication system of the present embodiment, respectively. 41 is a central conductor, 42 is a silver tube, and 43 is an insulator. The semi-rigid wire is covered with insulating rubber 44.

[0059] As in this embodiment, even when the semi-rigid wire 40 partially covered with the insulating rubber 44 is used instead of the cable 19 and the ferrite core 20, the electromagnetic wave generated on the outer surface of the body 10a. Does not adversely affect the signal transmitted on the semi-rigid line 40. Therefore, electromagnetic waves generated on the outer surface of the body 10a can be taken into the cabin 10b. it can.

 [0060] Reference is now made to FIG. FIG. 11 shows a side view of the toroidal core 50 used in the communication system of the present embodiment. The toroidal core 50 has a donut-shaped permanent magnet 51 covered with a shoreline 52. Even in the case where the toroidal core 50 is used instead of the ferrite core 20 as in this embodiment, the signal transmitted to the cable 19 is adversely affected by the electromagnetic waves generated on the outer surface of the body 10a. There is nothing. Therefore, electromagnetic waves generated on the outer surface of the body 10a can be taken into the cabin 10b.

 Example 3

 In the communication system of the present embodiment, an example in which an insulator is sandwiched between a conductor and a body, a cable is connected to the conductor, and a signal is taken into the body through a hole formed in the body. explain. Since other configurations are the same as those in the above-described embodiment, the description thereof is omitted here.

 [0062] Reference is made to FIG. As shown in FIG. 13, in this embodiment, the insulator 61 is sandwiched between the conductor 60 and the body 10a, the cable 19 is connected to the conductor 60, and the body 31a is opened through the hole 31. The signal is taken into 10a. The cable 19 may be a coaxial cable.

 [0063] As the insulator 61, it is preferable to use cellophane (dielectric constant 6.1 to 7.4), Teflon (registered trademark) (dielectric constant 2), etc., and acrylic resin (dielectric constant 2. 7-4.5), silicone resin (dielectric constant 3.5-5), etc. can be used.

 FIG. 14 is a graph showing transmission characteristics in the communication system of this example. Fig. 14 shows that when the signal frequency is changed from 45MHz to 60MHz, it is pulled into the inside of the body by the "tire" wheel one body body outer surface (trunk outer surface) cable "in the communication system of this embodiment. The frequency transmission characteristics of the communication channel are shown. From FIG. 14, it is understood that the communication characteristic of this embodiment is excellent in transmission characteristics with a frequency of about 45 MHz to about 50 MHz.

 [0065] According to the communication system of the present embodiment, electromagnetic waves generated on the outer surface of the body can be taken into the body using a simple configuration.

Example 4 [0066] In the communication system of the present embodiment, an example in which a signal is taken into the body by passing a bolt through a hole in the body and fixing the cable in contact with the inside of the body with a bolt and a nut will be described. To do. Since other configurations are the same as those in the above-described embodiment, the description thereof is omitted here.

 [0067] Reference is made to FIG. As shown in FIG. 15, in this embodiment, a bolt 60 is inserted into a hole 31 formed in the body 10a, and a cable 19 brought into contact with the inside of the body 10a through a washer 61 is fixed by a bolt and a nut 61. The signal is taken into the body 10a. The cable 19 may be a coaxial cable.

 [0068] According to the communication system of the present embodiment, electromagnetic waves generated on the outer surface of the body can be taken into the body using a simpler configuration.

 Example 5

 [0069] In the above-described embodiment and Examples 1 to 4, the power used to describe an example in which the communication system of the present invention is used for a tire pressure monitoring system. The application of the communication system of the present invention is limited to this. Therefore, it can be applied to various control systems in a vehicle such as a light control system that controls ON / OFF of light in a vehicle and a light control system, an air conditioner control system, and a video information control system using a source such as a DVD. Applicable.

 Industrial applicability

[0070] According to the communication system and the communication device of the present invention, it is possible to perform information communication in a vehicle with a simple configuration and high efficiency without using a conventional wire communication or a conventional wireless communication using an optical cable or an optical cable. .

Therefore, the communication system of the present invention can be used for a moving body such as a train, a car, a ship, an airplane, or any other vehicle.

Claims

The scope of the claims  [1] A vehicle, a first transceiver, and an electrical conductor of the vehicle that are connected to the first transceiver and are transmitted from the first transceiver based on a first signal transmitted from the first transceiver. A first exciter that receives the second signal transmitted from the conductor of the vehicle and transmits the second signal to the first transceiver, and a second transceiver installed inside the vehicle; The conductor of the vehicle is excited through a cable based on the second signal connected to the second transceiver and transmitted from the second transceiver; and the conductor of the vehicle A second exciter that receives the first signal transmitted from the first transmitter and transmits the signal to the second transceiver; a hole for introducing the cable into the vehicle; and A high-frequency noise prevention element that covers the cable.  2. The communication system according to claim 1, wherein the high-frequency noise preventing element is a ferrite core or a toroidal core.  [3] A vehicle, a first transmitter / receiver, and the first transmitter / receiver are connected to the first transmitter / receiver, and the electric conductor of the vehicle is excited based on a first signal transmitted from the first transmitter / receiver. A first exciter that receives the second signal transmitted from the conductor of the vehicle and transmits the second signal to the first transceiver, and a second transceiver installed inside the vehicle; The conductor of the vehicle is excited through a semi-rigid cable based on the second signal connected to the second transceiver and transmitted from the second transceiver. A second exciter that receives the first signal transmitted from the electric body and transmits the first signal to the second transceiver; a hole for introducing the semi-rigid cable into the vehicle; and And an insulator covering the cable.  [4] The communication system according to any one of claims 1 to 3, wherein a sensor is connected to the first transceiver.  [5] The communication system according to any one of claims 1 to 4, wherein a CPU is connected to the second transceiver. [6] A first transmitter / receiver, connected to the first transmitter / receiver, excites a vehicle conductor based on a first signal transmitted from the first transmitter / receiver, and the vehicle A first exciter that receives a second signal transmitted from the conductor and transmits the second signal to the first transceiver; A second transmitter / receiver installed inside the vehicle; and the vehicle connected to the second transmitter / receiver and through the cable based on the second signal transmitted from the second transmitter / receiver. A second exciter that receives the first signal transmitted from the conductor of the vehicle and transmits the first signal to the second transceiver; and A communication device having a hole for introducing the inside of the cable and a high-frequency noise prevention element that covers the cable in the hole. 7. The communication device according to claim 6, wherein the high frequency noise preventing element is a ferrite core or a toroidal core.  [8] A first transmitter / receiver, connected to the first transmitter / receiver, excites a vehicle conductor based on a first signal transmitted from the first transmitter / receiver, and the vehicle A first exciter for receiving a second signal transmitted from the conductor and transmitting the second signal to the first transceiver; a second transceiver installed in the vehicle; and the second transceiver Based on the second signal transmitted to the second transmitter / receiver, the conductor of the vehicle is excited through the semi-rigid cable and transmitted from the conductor of the vehicle. A second exciter for receiving the first signal transmitted to the second transceiver, a hole for introducing the semi-rigid cable into the vehicle, and covering the cable in the hole And a communication device having an insulator.  [9] The communication device according to any one of [6] to [8], wherein a sensor is connected to the first transceiver.  [10] The communication device according to any one of claims 6 to 9, wherein a CPU is connected to the second transceiver.