Wire harness, detection system, and detection method

Abstract

The wire harness connects communication between the first communication unit and the second communication unit. The wire harness includes a first connector, a second connector, and a cable disposed between the first connector and the second connector. The cable includes: a plurality of electric wires including an electric wire for detection; and a conductor for grounding the detection wire. The detection wire is an unshielded wire, and is disposed such that the impedance of the detection wire is a predetermined value.

Description

TECHNICAL FIELD

[0001] The present application relates to a wire harness, a detection system, and a detection method. The present application claims priority based on Japanese Patent Application No. 2023-075921 filed on May 2, 2023, and incorporates by reference the entire disclosure of the Japanese Patent Application. BACKGROUND

[0002] Various in-vehicle devices are mounted on a vehicle. The in-vehicle devices include various ECUs (Electronic Control Units) that are responsible for functions required for the vehicle such as steering and braking. These ECUs form a network by being connected to each other. The ECUs communicate with each other via the network, whereby basic functions in the vehicle such as “traveling”, “turning”, and “stopping” are realized. Communication between the in-vehicle devices generally uses a wire harness.

[0003] In such in-vehicle devices, a technology for preventing hacking or data falsification of the in-vehicle devices (ECUs) is required. Patent Literature 1 described later proposes a technology for suppressing illegal access in a connector for in-vehicle use.

[0004] The technology described in Patent Literature 1 relates to a safety structure of a connector. The safety structure includes a protective cover that is assembled in a manner of covering the connector in a fitted state. The protective cover can be released from fixation only by a dedicated jig. With the protective cover, the wire harness connected to the connector of the in-vehicle device cannot be easily detached. Therefore, according to the safety structure described in Patent Literature 1, illegal access to the in-vehicle device due to replacement of the connector or the wire harness and inspection of the communication line, and the like can be suppressed. PRIOR ART DOCUMENTS PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2017 / 047567 SUMMARY

[0006] The wire harness according to one aspect of the present application connects communication between a first communication portion and a second communication portion, the wire harness including a first connector and a second connector and a cable disposed between the first connector and the second connector. The cable includes a plurality of electric wires including a detection electric wire, and a conductor that functions as a ground for the detection electric wire. The detection electric wire is an electric wire having no shield and is disposed so that an impedance of the detection electric wire is a predetermined value.

[0007] The present application is not only realized as a wire harness, a detection system, or a detection method including such a characteristic structure, but also as a program for causing a computer to execute characteristic steps performed by the detection system or the detection method or a recording medium in which the program is recorded. Further, it is also realized as another system or device including the wire harness or the detection system. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a diagram showing a configuration example of a communication system of the first embodiment. Figure 2 is a diagram schematically showing Figure 1 a cross section of the wire harness shown in FIG. 2 along the line A-A. Figure 3 is a diagram showing Figure 2 a cross section of the detection electric wire shown in FIG. 3. Figure 4 is a diagram showing Figure 2 a cross section of the electric wire of the protection object shown in FIG. 4. Figure 5 is a block diagram for explaining Figure 1 a configuration example of the in-vehicle device shown in FIG. 5. Figure 6 is a block diagram showing a configuration example on a function of the detection device mounted on the in-vehicle device. Figure 7 is a diagram for explaining Figure 1 the communication system shown in FIG. 8. Figure 8 is a cross section showing a configuration example of a wire harness of a modification. Figure 9 is a cross section showing a configuration example of a wire harness of the second embodiment. Figure 10 is a diagram showing Figure 9 a cross section of the electric wire of the protection object shown in FIG. 12. Figure 11 is a diagram showing a configuration example of a communication system of the third embodiment. Figure 12 is a diagram schematically showing Figure 11 a cross section of the wire harness shown in FIG. 14 along the line B-B. Figure 13 is a diagram for explaining Figure 11 the communication system shown in FIG. 16, the diagram of the cable portion of the wire harness is a schematic plan view in which the description of the upper portion of the detection electric wire is omitted. Figure 14 is a diagram showing a configuration example of a communication system of the fourth embodiment. Figure 15 is a diagram schematically showing Figure 11 a cross section of the wire harness shown in FIG. 18 along the line C-C. Figure 16 is a diagram showing a configuration example of a communication system of the fifth embodiment. Figure 17 is a diagram for explaining Figure 16 the communication system shown in FIG. 22, the diagram of the cable portion of the wire harness is a schematic plan view in which the description of the upper portion of the detection electric wire is omitted.Figure 16 A diagram showing a cross section of the wire harness along the line D-D. DETAILED DESCRIPTION

[0009] [Problems to be Solved by the Invention] The safety structure described in Patent Literature 1 provided with a protective cover is easy to deal with because it is obvious from the appearance that safety measures have been taken. For example, in the case where the protective cover is physically damaged, illegal access to the in-vehicle device can be made.

[0010] The present invention was made in order to solve such a problem, and an object of the present invention is to provide a wire harness, a detection system, and a detection method that improve communication security by a configuration that is difficult to know from the appearance.

[0011] [Effects of the Invention] According to the present invention, it is possible to provide a wire harness, a detection system, and a detection method that improve communication security by a configuration that is difficult to know from the appearance.

[0012] [Explanation of Embodiments of the Invention] Preferred embodiments of the present invention will be described. At least a part of the embodiments described below can be combined arbitrarily.

[0013] (1) The wire harness of the first aspect of the present invention is a wire harness that connects communication between a first communication section and a second communication section. The wire harness includes a first connector and a second connector and a cable disposed between the first connector and the second connector. The cable includes a plurality of electric wires including a detection electric wire and a conductor that functions as a ground for the detection electric wire. The detection electric wire is an electric wire that does not have a shield and is disposed so that the impedance of the detection electric wire is a predetermined value.

[0014] For example, in the case of an inspection for the purpose of stealing information such as illegal access, the conductor is sometimes peeled off. Since the conductor functions as a ground for the detection electric wire, when the conductor is peeled off, the impedance of the detection electric wire changes. By detecting this change in impedance, it is possible to detect an inspection of the wire harness. Thus, it is possible to improve communication security. Communication security can be improved without using a member such as a protective cover that is easily known from the appearance, so it is difficult to know from the appearance whether or not safety measures have been taken.

[0015] (2) In the above (1), the plurality of electric wires can include a communication electric wire that is different from the detection electric wire. By providing the detection electric wire independently of the communication electric wire, it is easy to dispose the detection electric wire so that the impedance thereof is a predetermined value. Thus, it is possible to easily improve communication security.

[0016] (3) In the above (2), the communication electric wire can have a shield. Thus, it is possible to suppress degradation of communication performance.

[0017] (4) In the case of the above (2) or (3), the impedance of the detection electric wire can be made different from the impedance of the communication electric wire. This increases the degree of freedom in setting the impedance of the detection electric wire, and thus makes it easier to improve the communication security.

[0018] (5) In the case of the above (1), the plurality of electric wires can include a communication electric wire, and the communication electric wire can include the detection electric wire. That is, the communication electric wire can be configured to function as the detection electric wire. This eliminates the need to provide a separate detection electric wire, and thus makes it possible to reduce the number of electric wires in the cable. Therefore, even when the communication security is improved, it is possible to suppress an increase in the cost of the wire harness.

[0019] (6) In any one of the above (1) to (5), the cable can be flat. This makes it easy to fix the positional relationship between the conductor that functions as a ground and the detection electric wire, and thus makes it possible to stabilize the impedance of the detection electric wire. This makes it easy to detect a change in the impedance, and thus makes it possible to improve the detection accuracy of an illegal access.

[0020] (7) In the case of the above (6), the conductor can include a sheet-shaped conductor. This makes it easy to cause a change in the impedance of the detection electric wire when performing the inspection, and thus makes it possible to further improve the detection accuracy of an illegal access.

[0021] (8) In the case of the above (7), the sheet-shaped conductor can include a first conductor sheet and a second conductor sheet, and the detection electric wire can be disposed between the first conductor sheet and the second conductor sheet. This makes it possible to peel the sheet-shaped conductor regardless of which side, the upper surface side or the lower surface side, the inspection is performed from, in the flat cable, and thus makes it possible to effectively detect a change in the impedance of the detection electric wire. Therefore, it is possible to further improve the communication security.

[0022] (9) In any one of the above (6) to (8), in the case where a specific electric wire included in the plurality of electric wires is a target of protection, the detection electric wire can be disposed in the same layer as a layer in which the electric wire that is the target of protection is disposed. This makes it possible to more reliably cause a change in the impedance of the detection electric wire when performing the inspection, and thus makes it possible to further improve the communication security.

[0023] (10) In any one of the above (6) to (8), the cable can have a stacked structure in which the plurality of electric wires are disposed in a plurality of layers, and the detection electric wire can be disposed in an outermost layer in the stacked structure. The outermost layer in the stacked structure is peeled first when performing the inspection. Therefore, by disposing the detection electric wire in this layer, it is possible to easily detect a sign of an illegal access. Further, by being configured in this way, it is possible to reduce the constraints on the wiring with respect to other electric wires. For example, in the case where a specific electric wire included in the plurality of electric wires is a target of protection, it is possible to dispose the electric wire that is the target of protection in a different layer from the detection electric wire.

[0024] (11) In any one of the above (6) to (8), it can also be configured such that the cable has a layered structure in which a plurality of electric wires are arranged in a plurality of layers, and the detection electric wire is arranged across the layers. Thus, when inspection is performed, the impedance of the detection electric wire can be easily changed. Therefore, by thus configuring, communication security can be further improved.

[0025] (12) The detection system of the second aspect of the present application includes a wire harness and a detection device electrically connected to the wire harness. The wire harness includes a first connector and a second connector and a cable arranged between the first connector and the second connector. The cable includes a plurality of electric wires including a detection electric wire and a conductor that functions as a ground for the detection electric wire. The detection electric wire is an electric wire that does not have a shield and is arranged such that the impedance of the detection electric wire is a predetermined value. The detection device includes a measurement section that measures the impedance of the detection electric wire and a determination section that determines whether or not illegal communication is performed based on the measurement result of the impedance by the measurement section.

[0026] For example, if the conductor is peeled off when inspection for the purpose of stealing information such as illegal access is performed, the impedance of the detection electric wire changes. The measurement section of the detection device measures the impedance of the detection electric wire. The determination section determines whether or not illegal communication caused by the inspection or the like is performed based on the measurement result of the impedance. Thus, communication security can be improved. Communication security can be improved without using a member such as a protective cover that is easily known from the appearance, so it is difficult to know from the appearance whether or not a security countermeasure is taken.

[0027] (13) In the above (12), the determination section can be configured to determine that illegal communication is performed in response to the impedance of the detection electric wire changing by a predetermined threshold value or more. Thus, it can be easily determined whether or not illegal communication caused by the inspection or the like is performed.

[0028] (14) The detection method of the third aspect of the present application is a detection method of detecting illegal communication in communication via a wire harness. The cable of the wire harness includes a plurality of electric wires including a detection electric wire and a conductor that functions as a ground for the detection electric wire. The detection electric wire is an electric wire that does not have a shield and is arranged such that the impedance of the detection electric wire is a predetermined value. The detection method measures the impedance of the detection electric wire and determines whether or not illegal communication is performed based on the measurement result. Thus, in addition to being able to improve communication security, it is also difficult to know from the appearance whether or not a security countermeasure is taken.

[0029] (15) In the above (14), the detection method can be configured to determine that illegal communication is performed in response to the impedance of the detection electric wire changing by a predetermined threshold value or more. Thus, it can be easily determined whether or not illegal communication caused by the inspection or the like is performed.

[0030] [Details of Embodiments of the Present Invention] Embodiments of the harness, the detection system, or the detection method of the present application will be described below with reference to the accompanying drawings. In addition, in the following embodiments, the same reference numerals are assigned to the same components. Their functions and names are also the same. Therefore, detailed explanations about those will not be repeated.

[0031] (First Embodiment) [Overall Configuration] Referring to Figure 1 The harness 100 of the present embodiment is a harness for communication between in-vehicle devices. The in-vehicle devices include a first in-vehicle device 60 and a second in-vehicle device 70. The first in-vehicle device 60 includes a first communication section 62, and the second in-vehicle device 70 includes a second communication section 72. The harness 100 connects communication between the first communication section 62 and the second communication section 72.

[0032] In the present embodiment, the harness 100 is directly connected to the first in-vehicle device 60 and the second in-vehicle device 70. However, the harness 100 can be configured to be indirectly connected to the first in-vehicle device 60 or the second in-vehicle device 70 via other harnesses or the like.

[0033] It is assumed that the first in-vehicle device 60 and the second in-vehicle device 70 are both ECUs. In this case, the first communication section 62 and the second communication section 72 include a PHY (Physical layer). The PHY is configured by a chip (integrated circuit) mounted to the ECU that performs transmission and reception of signals.

[0034] The first in-vehicle device 60 includes a substrate 64 on which the first communication section 62 is mounted, and a connector 66. The connector 66 and the first communication section 62 are electrically connected by a wiring section not shown. The second in-vehicle device 70 includes a substrate 74 on which the second communication section 72 is mounted, and a connector 76. The connector 76 and the second communication section 72 are electrically connected by a wiring section not shown.

[0035] The harness 100 includes a first connector 102 and a second connector 104, and a cable 110 disposed between the first connector 102 and the second connector 104. The first connector 102 is connected to a first end portion of the cable 110, and the second connector 104 is connected to a second end portion of the cable 110. The first connector 102 is connected to the connector 66 of the first in-vehicle device 60, and the second connector 104 is connected to the connector 76 of the second in-vehicle device 70. In addition, in a case where the cable 110 extends in a straight line, the direction in which the cable 110 extends is taken as an LI direction.

[0036] Referring to Figure 2The cable 110 of the wire harness 100 has a configuration in which a plurality of electric wires are bundled by an insulating outer member 112. The outer member 112 is, for example, an insulating covering portion that covers the plurality of electric wires. The plurality of electric wires sometimes include an electric wire that transmits information having a high level of confidentiality. Such an electric wire needs to be protected from illegal access, and is therefore sometimes referred to as a "protected electric wire" hereinafter. Here, a specific electric wire included in the plurality of electric wires is set as the protected electric wire 120.

[0037] A conductor 114 is inserted inside the outer member 112, and the conductor 114 functions electrically as a ground. Specifically, the conductor 114 is configured of, for example, a conductive material such as a metal material, and covers the plurality of electric wires. The outer member 112 covers the plurality of electric wires via the conductor 114.

[0038] The plurality of electric wires include a detection electric wire 130. The detection electric wire 130 is an electric wire that has no shield. The conductor 114 functions as a ground with respect to the detection electric wire 130. The detection electric wire 130 is configured (designed) so that its impedance (characteristic impedance) is a predetermined value (sometimes referred to as a "specified value" hereinafter) by adjusting the positional relationship with the conductor 114 and the material of a member disposed between the conductor 114, and the like. The predetermined value can be set to 50 ± 10 Ω, for example. The predetermined value is not limited to this, and can be set to a value other than this.

[0039] Referring to Figure 3 , the detection electric wire 130 includes a conductive core wire 132 and an insulating covering portion 134 that covers the core wire 132. The adjustment of the impedance of the detection electric wire 130 can also be performed by adjusting the thickness of the insulating covering portion 134 (the thickness of the covering material) or changing the material of the insulating covering portion 134.

[0040] Referring to Figure 4 , the protected electric wire 120 is an electric wire that has a shield. The protected electric wire 120 includes a core wire 122, a dielectric body 124 that covers the core wire 122, a metal shield portion 126 that is disposed outside the dielectric body 124, and an insulating covering portion 128 that covers the metal shield portion 126. The impedance (characteristic impedance) of the protected electric wire 120 is 50 Ω, for example. Other electric wires than the detection electric wire 130 also have the same configuration as the protected electric wire 120. The plurality of electric wires including the protected electric wire 120 can also be electric wires that have no shield.

[0041] [Communication system 50] Referring again to Figure 1The communication system 50 of the present embodiment includes the wire harness 100 described above and a detection device 150 electrically connected to the wire harness 100. The detection device 150 performs inspection and the like by monitoring a change in impedance of the detection electric wire 130. In the present embodiment, the first in-vehicle device 60 includes the detection device 150. That is, the first in-vehicle device 60 also functions as the detection device 150. The detection device 150 can be included in the configuration of the second in-vehicle device 70 or in the configurations of both the first in-vehicle device 60 and the second in-vehicle device 70. The detection device 150 can also be mounted on an in-vehicle device that holds information with high confidentiality.

[0042] Referring to Figure 5 , the first in-vehicle device 60 includes, in addition to the first communication section 62, a control section 80 and a storage section 82. The control section 80 includes, for example, a calculation element (processor) such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The storage section 82 includes a nonvolatile memory such as a flash memory. In the storage section 82, software (computer program) executed by the control section 80 and various information (data) are stored. The functions of the respective functional sections of the first in-vehicle device 60 are realized by software processing performed by the control section 80 using hardware. The first in-vehicle device 60 also has a function as the detection device 150. Part or all of these functions can also be realized by an integrated circuit including a microcomputer.

[0043] Referring to Figure 6 , the detection device 150 includes, as functional sections, an impedance monitoring section 152 that monitors a change in impedance of the detection electric wire 130 (see Figure 2 ) and a communication restriction section 158 that restricts communication via the wire harness 100 based on a monitoring result of the impedance monitoring section 152. The impedance monitoring section 152 includes a measurement section 154 that measures the impedance of the detection electric wire 130 and a determination section 156 that determines whether or not illegal communication is performed based on a measurement result of the impedance by the measurement section 154. The determination section 156 determines that illegal communication is performed in response to a change in impedance of the detection electric wire 130 being equal to or greater than a predetermined threshold value. The predetermined threshold value is set in advance and stored in the storage section 82 (see Figure 5 ). The determination section 156 makes a determination with appropriate reference to the threshold value stored in the storage section 82.

[0044] The communication restriction section 158 restricts communication in a case where it is determined that illegal communication is performed. Specifically, the communication restriction section 158 cuts off communication in a case where it is determined that illegal communication is performed. However, it is also possible to continue a part of the communication without cutting off all of the communication. For example, it is also possible to continue communication with respect to information with low confidentiality based on an electric wire other than the protected electric wire 120.

[0045] The ECU, which is one of the in-vehicle devices, has an impedance measurement function using TDR (Time Domain Reflectometry). The TDR is a method of measuring a change (discontinuity point) in a characteristic impedance of a wire by transmitting a pulse signal or a step signal to a measurement target and observing a returned reflected waveform.

[0046] In a case where the first in-vehicle device 60 is an ECU having such a function, the detection device 150 can also monitor a change in impedance of the detection wire 130 using the impedance measurement function of the TDR.

[0047] The second in-vehicle device 70 can also have the same configuration as the first in-vehicle device 60. However, the second in-vehicle device 70 can be either a configuration including the detection device or a configuration not including the detection device.

[0048] Reference Signs Figure 7 The detection device 150 of the first in-vehicle device 60 is electrically connected to the detection wire 130. The measurement unit 154 of the detection device 150 (refer to Figure 6 ) measures a characteristic impedance of the detection wire 130, for example, by the TDR method.

[0049] When a test for the purpose of stealing information such as illegal access is performed, the outer cover 112 and the conductor 114 are peeled off. Since the conductor 114 functions as a ground for the detection wire 130, when the conductor 114 is peeled off, a change in impedance of the detection wire 130 occurs. More specifically, when the outer cover 112 and the conductor 114 in the cable 110 are partially peeled off for the test, the impedance of the detection wire 130 greatly deviates from a prescribed value in the peeled-off portion. In a case where the impedance of the detection wire 130 deviates by more than a threshold value, it is likely that the test is performed, and thus the impedance monitoring unit 152 of the detection device 150 (refer to Figure 6 ) detects such a change in impedance, and determines that illegal communication is performed. The detection device 150 restricts communication when it is determined that illegal communication is performed.

[0050] Thus, according to the cable harness 100 or the communication system 50 of the present embodiment, a sign of a test or the like for illegal access can be detected in advance, and thus communication security can be improved. Furthermore, since the communication security can be improved without using a member such as a protective cover that is easily known from the appearance, it is difficult to know whether or not a security countermeasure is taken from the appearance.

[0051] The plurality of electric wires included in the cable 110 include a communication electric wire (a protected electric wire 120) that is different from the detection electric wire 130. By providing the detection electric wire 130 separately from the protected electric wire 120, it is easy to arrange the detection electric wire 130 so that its impedance is a predetermined value (a prescribed value). Thus, it is easy to improve communication security.

[0052] By using an electric wire having a shield in the protected electric wire 120, it is possible to suppress degradation of communication performance.

[0053] (Modified Example) In the above-described embodiment, it is also possible to arrange (design) the detection electric wire 130 so that its impedance is a prescribed value by interposing another dielectric body between the detection electric wire 130 and the conductor 114. Hereinafter, an example of such a configuration will be described.

[0054] Reference Figure 8 In the cable 110A of the modified example, a dielectric body 116 is arranged between the conductor 114 and the detection electric wire 130. The dielectric body 116 is, for example, an insulating covering portion having a predetermined thickness, which covers a plurality of electric wires including the detection electric wire 130 and the protected electric wire 120. The conductor 114 is arranged between the outer member 112 and the dielectric body 116. By adjusting the thickness or material of the dielectric body 116, the impedance of the detection electric wire 130 is set to a prescribed value.

[0055] Further, the dielectric body interposed between the detection electric wire 130 and the conductor 114 can be a dielectric body other than an insulating covering portion. For example, the dielectric body can be a configuration in which a portion of the detection electric wire 130 is locally interposed between the conductor 114.

[0056] The other configuration is the same as that of the above-described first embodiment.

[0057] (Second Embodiment) Reference Figure 9 The wire harness 200 of the present embodiment differs from the first embodiment in that the protected electric wire 220 functions as a detection electric wire. Thus, the protected electric wire 220 is an electric wire that does not have a shield. The conductor 114 functions as a ground for the protected electric wire 220 that functions as a detection electric wire. The protected electric wire 220 is also a detection electric wire, and thus is arranged (designed) so that its impedance (characteristic impedance) is a predetermined value (a prescribed value) by adjusting the positional relationship with the conductor 114 and the material of a member arranged between the conductor 114. The predetermined value is the same as described above, and can be set to 50 ± 10 Ω, for example.

[0058] Reference Figure 10The electric wire (detection electric wire) 220 that is the protection target includes a core wire 222 that is electrically conductive and an insulating covering portion 224 that covers the core wire 222.

[0059] With this configuration, it is not necessary to separately provide a detection electric wire. Thus, it is possible to achieve a reduction in the number of electric wires of the wire harness. As a result, even in the case of improving communication security, it is possible to suppress an increase in the cost of the wire harness.

[0060] The other configurations and effects are the same as those of the first embodiment.

[0061] (Third Embodiment) Referring to Figure 11 , the communication system 50A of the present embodiment differs from the first and second embodiments in that the wire harness 300 is included instead of the wire harness 100 (refer to Figure 1 ).

[0062] The wire harness 300 includes a first connector 302 and a second connector 304 and a wire harness 310 disposed between the first connector 302 and the second connector 304. The first connector 302 is connected to a first end portion of the wire harness 310, and the second connector 304 is connected to a second end portion of the wire harness 310. The wire harness 310 is a flat wire harness that is flat. Further, in the case where the wire harness 310 extends in a straight line, the direction in which the wire harness 310 extends is taken as the L2 direction.

[0063] Referring to Figure 12 , the wire harness 310 of the wire harness 300 has a stacked structure in which a plurality of electric wires are disposed in a plurality of layers. In Figure 12 , an example of a stacked structure in which the number of layers is four layers is shown. However, the number of layers of the stacked structure is not limited to four layers, and can be two layers, three layers, or five or more layers.

[0064] The plurality of electric wires include a protection target electric wire 320 and a detection electric wire 330. The protection target electric wire 320 has the same configuration as the protection target electric wire 120 (refer to Figure 4 ) shown in the first embodiment. The detection electric wire 330 is an electric wire that does not have a shield, and has the same configuration as the detection electric wire 130 (refer to Figure 3 ) shown in the first embodiment.

[0065] Multiple wires are held by sheet-like retaining members. The retaining members include a first sheet 340, a second sheet 342, and a third sheet 344, all of which are flexible insulating sheets. The first sheet 340, the second sheet 342, and the third sheet 344 are, for example, formed to be the same size. The retaining members also include sheet-like conductors 350. The sheet-like conductors 350 include a first conductor sheet 352 and a second conductor sheet 354. The first conductor sheet 352 and the second conductor sheet 354 are, for example, formed to be the same size as the first sheet 340, the second sheet 342, and the third sheet 344. The first sheet 340 and the third sheet 344 function as outer casings.

[0066] The wires on each layer are held in place by two sheet-like retaining members and fixed to the retaining members arranged above and below. The wires can be fixed to the retaining members by means of ultrasonic welding, laser welding, or adhesive.

[0067] The detection wire 330 is disposed on the same layer as the wire 320 of the protected object. The detection wire 330 and the wire 320 of the protected object are held together by the first conductor plate 352 and the second conductor plate 354. That is, the detection wire 330 and the wire 320 of the protected object are disposed between the first conductor plate 352 and the second conductor plate 354. More specifically, the detection wire 330 is fixed to the first conductor plate 352 and the second conductor plate 354. Similar to the first embodiment, the characteristic impedance of the detection wire 330 is adjusted to a predetermined value (specified value) by appropriately changing the thickness or material of the dielectric material disposed between it and the first conductor plate 352 and the second conductor plate 354.

[0068] Reference Figure 13 The detection device 150 of the first vehicle-mounted device 60 is electrically connected to the detection wire 330. The measuring section 154 of the detection device 150 (see reference) Figure 6 For example, the characteristic impedance of the test wire 330 can be determined by the TDR method.

[0069] Refer again Figure 12 When conducting inspections for purposes such as unauthorized access or information theft, the first sheet is stripped. Since the protected wire 320 is located in the same layer as the inspection wire 330, when inspecting from the upper surface of the cable 310, the first sheet 340, the second sheet 342, and the first conductor sheet 352 are stripped. Conversely, when inspecting from the lower surface of the cable 310, the third sheet 344 and the second conductor sheet 354 are stripped. In all cases, the sheet conductor 350 is stripped along with the outer casing.

[0070] Since the sheet conductor 350 functions as a ground for the detection electric wire 330, when the conductor 350 is peeled, the impedance of the detection electric wire 330 changes. In a case where the impedance of the detection electric wire 330 deviates from a threshold value or more, it is likely that the inspection is intended, so the impedance monitoring section 152 of the detection device 150 (refer to Figure 6 ) determines that the illegal communication is performed when such an impedance change is detected. The detection device 150 restricts the communication when it is determined that the illegal communication is performed.

[0071] The flat wire harness has advantages that it can have various functions such as sound deadening, sound absorbing, wear resistance, heat dissipation, shielding, waterproofing, and the like according to the function of the outer member (retaining member), but has a disadvantage that the inspection of the peeled sheet is easy since the sheet outer member is easily peeled.

[0072] The wire harness 300 and the communication system 50A including the wire harness 300 of the present embodiment can detect a sign of illegal access such as inspection in advance, so it can enjoy the advantages of the conventional wire harness while preventing illegal access and the like caused by the inspection.

[0073] The flat cable 310 can easily fix the positional relationship of the conductor 350 functioning as a ground and the detection electric wire 330, so it can make the impedance of the detection electric wire 330 more stable. Since the change in the impedance can be easily detected, the detection accuracy of the illegal access can be improved.

[0074] Further, by forming the conductor into the sheet conductor 350, the sheet conductor 350 needs to be peeled in order to expose the electric wire 320 to be protected when the inspection is performed. In this way, the conductor 350 is necessarily peeled when the inspection is performed, so the impedance of the detection electric wire 330 can be easily changed. Thus, the detection accuracy of the illegal access can be further improved.

[0075] Further, by arranging the detection electric wire 330 between the first conductor sheet 352 and the second conductor sheet 354, in the flat cable 310, the sheet conductor 350 is peeled in a case where the inspection is performed from either the upper surface side or the lower surface side. Thus, the change in the impedance of the detection electric wire 330 can be effectively detected, so the communication security can be further improved.

[0076] The other configurations and effects are the same as those of the first embodiment.

[0077] (4th Embodiment) Referring to Figure 14 , the communication system 50B of the present embodiment is different from the third embodiment in that it includes a wire harness 400 instead of the wire harness 300 (refer to Figure 11 ). The wire harness 400 includes a cable 410 instead of the cable 310 (refer to Figure 11 ).

[0078] Referring to Figure 15 The cable 410 of the wire harness 400 is, as with the third embodiment, a flat cable having a stacked structure in which a plurality of electric wires are arranged in layers. The plurality of electric wires include the object wire 320 and the detection wire 330. The plurality of electric wires are held by sheet-like holding members.

[0079] The holding members include a first sheet 420, a second sheet 422, a third sheet 424, and a fourth sheet 426, each of which is an insulating sheet having flexibility. The first sheet 420 and the fourth sheet 426 function as outer members. The holding members further include a sheet-like conductor 350. The sheet-like conductor 350 includes a first conductor sheet 352 and a second conductor sheet 354.

[0080] In the present embodiment, the detection wire 330 is arranged in the outermost layer in the stacked structure. The arrangement of the object wire 320 is arbitrary. Here, the object wire 320 is arranged in a layer different from the detection wire 330. However, the object wire 320 can be configured to be arranged in the same layer as the detection wire 330. The detection wire 330 is arranged between the first conductor sheet 352 and the second conductor sheet 354.

[0081] When an inspection for the purpose of stealing information such as illegal access is performed, the sheets are first peeled off. At this time, the sheets from the outer sheet are sequentially peeled off until the layer in which the object wire 320 is arranged. Therefore, by arranging the detection wire 330 in the outermost layer, the conductor 350 (352) of the layer in which the detection wire 330 is arranged is first peeled off. Thus, it is possible to easily detect a sign of an inspection or the like.

[0082] Further, by being thus configured, it is possible to detect the implementation of an inspection without arranging the object wire 320 in the same layer as the detection wire 330, so it is possible to reduce wiring constraints on other electric wires including the object wire 320. Therefore, for example, it is possible to arrange the object wire 320 in a layer different from the detection wire 330.

[0083] Other configurations and effects are the same as those of the third embodiment.

[0084] Further, in the above-described embodiments, an insulating sheet having flexibility can be used instead of the second conductor sheet 354. Further, a sheet-like conductor can be used instead of the second sheet 422. Also, a sheet-like conductor can be used instead of the third sheet 424.

[0085] (Fifth Embodiment) Referring to Figure 16 The communication system 50C of the present embodiment is configured to replace the wire harness 300 (refer to Figure 11) and differs from the third embodiment in that it includes a wire harness 500. The wire harness 500 replaces the cable 310 (refer to Figure 11 ) and includes a cable 510.

[0086] The cable 510 of the wire harness 500 is, like the third embodiment, a flat cable having a stacked structure in which a plurality of electric wires are arranged in a plurality of layers. The plurality of electric wires include a protection target electric wire and a detection electric wire. The plurality of electric wires are held by a sheet-shaped holding member.

[0087] Refer to Figure 17 , the holding member includes a first sheet 520 and a second sheet 522, both of which are insulating sheets having flexibility. The first sheet 520 and the second sheet 522 function as an outer member. The holding member further includes a sheet-shaped conductor 530. The sheet-shaped conductor 530 includes a first conductor sheet 532, a second conductor sheet 534, a third conductor sheet 536, a fourth conductor sheet 538, and a fifth conductor sheet 540. Through-holes are formed in the second conductor sheet 534, the third conductor sheet 536, and the fourth conductor sheet 538, and a detection electric wire 550 is inserted through the through-holes. The detection electric wire 550 is an electric wire having no shield and has the same configuration as the detection electric wire 130 (refer to Figure 3 ) shown in the first embodiment.

[0088] The detection electric wire 550 is arranged across layers via the through-holes formed in the second conductor sheet 534, the third conductor sheet 536, and the fourth conductor sheet 538. Thus, because the detection electric wire 550 is arranged in a plurality of layers, the impedance of the detection electric wire 550 changes regardless of which layer of the stacked structure the conductor is peeled off. Thus, it is easy to configure such that the impedance of the detection electric wire 550 changes when inspection is performed. Therefore, by being thus configured, it is possible to further improve communication security.

[0089] The other configurations and effects are the same as those of the third or fourth embodiment.

[0090] (Modified Example) In the above-described embodiments, an example of a wire harness including one detection electric wire is shown. However, the present application is not limited to such an embodiment. The wire harness can also be configured to include a plurality of detection electric wires. In this case, a plurality of detection devices can also be provided in correspondence with the plurality of detection electric wires.

[0091] In the above-described embodiment, an example in which the characteristic impedance of the detection electric wire is set to the same degree as that of the electric wire of the protection target is shown. However, the present application is not limited to such an embodiment. The characteristic impedance of the detection electric wire can also be set to a value (a prescribed value) different from the characteristic impedance of the electric wire of the protection target or other electric wire. For example, in a case where the characteristic impedance of the other electric wire is set to 50 Ω, the detection electric wire can also be set to a characteristic impedance of, for example, 35 Ω to 40 Ω. Thereby, the degree of freedom in setting the impedance of the detection electric wire can be improved, so the communication security can be more easily improved.

[0092] In the above-described embodiment, an example in which it is determined that illegal communication is performed in a case where the characteristic impedance of the detection electric wire changes by more than a predetermined threshold value is shown. However, the present application is not limited to such an embodiment. For example, it can be determined that illegal communication is performed in a case where the difference between the characteristic impedance of the detection electric wire and the characteristic impedance of the other electric wire having a shield increases by more than a predetermined value. Further, it can be determined that illegal communication is performed in a case where the fluctuation range of the characteristic impedance of the detection electric wire from the history increases by more than a predetermined value.

[0093] In the above-described embodiment, an example in which the characteristic impedance of the detection electric wire is measured using the TDR method is shown. However, the present application is not limited to such an embodiment. The measurement of the characteristic impedance of the detection electric wire can also be performed using a method other than the TDR method.

[0094] In the above-described embodiment, an example in which the electric wire other than the detection electric wire in the wire harness is configured to have a shield is shown. However, the present application is not limited to such an embodiment. The electric wire other than the detection electric wire can be configured to have a shield or can be configured not to have a shield.

[0095] In the above-described embodiment, an example in which the flat wire harness has a laminated structure in which a plurality of layers are laminated is shown. However, the present application is not limited to such an embodiment. The flat wire harness can also be a single-layer structure having only one layer.

[0096] In the above-described embodiment, an example in which the flat wire harness is configured such that the detection electric wire is held by two conductor sheets is shown. However, the present application is not limited to such an embodiment. In the flat wire harness, the conductor sheet can also be configured to be provided on only one side of the detection electric wire.

[0097] Embodiments obtained by appropriately combining the above-described disclosed technologies are also included in the technical scope of the present application.

[0098] The embodiments disclosed this time are mere examples, and the present application is not only limited to the above-described embodiments. The scope of the present application is shown by each of the claims in the patent application, and includes all modifications within the meaning and range equivalent to the recitations of the claims. Reference Signs

[0099] 50, 50A, 50B, 50C communication system 60 first in-vehicle device 62 first communication section 64, 74 substrate 66, 76 connector 70 second in-vehicle device 72 second communication section 80 control section 82 storage section 100, 200, 300, 400, 500 wire harness 102, 302 first connector 104, 304 second connector 110, 110A, 310, 410, 510 cable 112 outer member 114 conductor 116, 124 dielectric body 120, 220, 320 electric wire for protection object 122, 132, 222 core wire 126 metal shield 128, 134, 224 insulating covering 130, 330, 550 electric wire for detection 150 detection device 152 impedance monitoring section 154 measurement section 156 determination section 158 communication restriction section 340, 420, 520 first sheet 342, 422, 522 second sheet 344, 424 third sheet 350, 530 sheet conductor 352, 532 first conductor sheet 354, 534 second conductor sheet 426 fourth sheet 536 third conductor sheet 538 fourth conductor sheet 540 fifth conductor sheet

Claims

1. A wire harness that connects communication between a first communication unit and a second communication unit, comprising a first connector and a second connector and a cable disposed between the first connector and the second connector, the cable comprising a plurality of electric wires including a detection electric wire; and a conductor that functions as a ground for the detection electric wire, the detection electric wire being an electric wire that does not have a shield and is disposed so that an impedance of the detection electric wire is a predetermined value.

2. The wire harness according to claim 1, wherein the plurality of electric wires include a communication electric wire that is different from the detection electric wire.

3. The wire harness according to claim 2, wherein the communication electric wire has a shield.

4. The wire harness according to claim 2 or claim 3, wherein the impedance of the detection electric wire is different from an impedance of the communication electric wire.

5. The wire harness according to claim 1, wherein the plurality of electric wires include a communication electric wire, the communication electric wire includes the detection electric wire.

6. The wire harness according to any one of claims 1 to 5, wherein the cable is flat.

7. The wire harness according to claim 6, wherein the conductor includes a sheet conductor.

8. The wire harness according to claim 7, wherein the sheet conductor includes a first conductor sheet and a second conductor sheet, the detection electric wire is disposed between the first conductor sheet and the second conductor sheet.

9. The wire harness according to any one of claims 6 to 8, wherein in a case where a specific electric wire included in the plurality of electric wires is an electric wire that is an object of protection, the detection electric wire is disposed in the same layer as a layer in which the electric wire that is the object of protection is disposed.

10. The wire harness according to any one of claims 6 to 8, wherein the cable has a layered structure in which the plurality of electric wires are disposed in a plurality of layers, the detection electric wire is disposed in an outermost layer in the layered structure.

11. The wire harness according to any one of claims 6 to 8, wherein the cable has a layered structure in which the plurality of electric wires are disposed in a plurality of layers, the detection electric wire is disposed across layers.

12. A detection system comprising a wire harness and a detection device that is electrically connected to the wire harness, the wire harness comprising a first connector and a second connector and a cable disposed between the first connector and the second connector, the cable comprising: a plurality of electric wires including a detection electric wire; and a conductor that functions as a ground for the detection electric wire, the detection electric wire being an electric wire that does not have a shield and is disposed so that an impedance of the detection electric wire is a predetermined value, the detection device comprising: a measurement unit that measures the impedance of the detection electric wire; and a determination unit that determines whether or not illegal communication is performed based on a result of the measurement of the impedance by the measurement unit.

13. The detection system according to claim 12, wherein the determination unit determines that illegal communication is performed in response to a change in the impedance of the detection electric wire being equal to or greater than a predetermined threshold value.

14. A detection method that detects illegal communication in communication via a wire harness, a plurality of electric wires including a detection electric wire; and ​ The cables of the wire harness include: ​ and a conductor that functions as a ground for the detection electric wire, which is an electric wire without a shield, is configured such that an impedance of the detection electric wire is a predetermined value, The detection method measures an impedance of the detection electric wire, and determines whether or not illegal communication is performed based on a result of the measurement.

15. The detection method according to claim 14, wherein The detection method determines that illegal communication is performed in response to a change in the impedance of the detection electric wire being equal to or greater than a predetermined threshold value.

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