Wire harness, harness identification system, and on-vehicle device

Abstract

This wire harness that connects communication between a first communication unit and a second communication unit includes: a transmission line that is provided between the first communication unit and the second communication unit and transmits a signal from at least one of the first communication unit and the second communication unit; and a filter unit that is provided at a predetermined position of the transmission line and has predetermined characteristics.

Description

Wire harness, harness identification system, and on-board device

[0001] The present disclosure relates to a wire harness, a harness identification system, and an in-vehicle device.

[0002] Vehicles are equipped with various on-board devices. These devices include various ECUs (Electronic Control Units) that control functions necessary for the vehicle, such as steering and braking. These ECUs are connected to each other to form a network. Each ECU communicates with each other via this network to realize basic vehicle functions, such as "driving," "turning," and "stopping." Wiring harnesses are usually used to connect the on-board devices.

[0003] Such in-vehicle devices require technology to prevent hacking or data tampering of the in-vehicle devices (ECUs).Patent Document 1, listed below, proposes a connector system for preventing communication between a wire harness and an unintended device.

[0004] The connector system described in Patent Document 1 includes a first connector and a second connector connected thereto. The second connector includes a processing unit that creates verification information and transmits it to the first connector. The first connector includes a verification unit that verifies the second connector based on the verification information received from the second connector. The verification unit determines that verification has failed if it is unable to receive the verification information. The first connector further includes a switch that, when connected to the second connector, switches between electrically connecting the transmission line in the first connector and the transmission line in the second connector, and a control unit that controls the switch based on the verification results of the verification unit.

[0005] If the second connector is an unauthorized connector, the verification unit of the first connector determines that the verification has failed. The control unit of the first connector maintains the switch in the off state. This interrupts the electrical connection between the transmission line of the first connector and the transmission line of the second connector. This prevents communication between the wire harness and unintended devices, ensuring the security of communication between devices.

[0006] International Publication No. 2019 / 187349

[0007] A wire harness according to one aspect of the present disclosure is a wire harness that connects communication between a first communication unit and a second communication unit, and includes a transmission line that is provided between the first communication unit and the second communication unit and transmits a signal from at least one of the first communication unit and the second communication unit, and a filter unit that is provided at a predetermined position on the transmission line and has predetermined characteristics.

[0008] The present disclosure can be realized not only as a wire harness, a harness identification system, or an on-board device including such a characteristic configuration, but also as a recording medium storing a program for causing a computer to execute the characteristic steps executed by the on-board device or the harness identification system. Furthermore, the present disclosure can be realized as other systems or devices including the wire harness, the harness identification system, or the on-board device.

[0009] FIG. 1 is a diagram illustrating an example of the configuration of a system according to a first embodiment. FIG. 2 is a diagram illustrating an example of the configuration of the wire harness shown in FIG. 1. FIG. 3A is a diagram illustrating an example of a filter unit provided in the wire harness shown in FIG. 1, and is also a diagram illustrating an example of an open stub constituting the filter unit. FIG. 3B is a diagram illustrating an example of a filter unit provided in the wire harness shown in FIG. 1, and is also a diagram illustrating an example of the frequency characteristics of the open stub. FIG. 4 is a diagram illustrating the characteristics of a filter unit provided in the wire harness shown in FIG. 1. FIG. 5 is a diagram illustrating an example of the configuration of an in-vehicle device shown in FIG. 1. FIG. 6 is a block diagram illustrating an example of the configuration of an identification device shown in FIG. 5. FIG. 7 is a diagram illustrating an example of the characteristics of a filter unit in a wire harness according to a second embodiment. FIG. 8 is a diagram illustrating an example of the configuration of a wire harness according to a third embodiment. FIG. 9A is a diagram illustrating a filter unit provided in the wire harness shown in FIG. 8, and is also a diagram illustrating an example of a filter exhibiting capacitive reflection characteristics. FIG. 9B is a diagram illustrating a filter unit provided in the wire harness shown in FIG. 8, and is also a diagram illustrating an example of a filter exhibiting inductive reflection characteristics. Fig. 10 is a diagram showing an example of the characteristics of a filter unit in a wire harness according to a third embodiment. Fig. 11 is a diagram for explaining a configuration example of a wire harness according to a fourth embodiment. Fig. 12 is a diagram for explaining a configuration example of a wire harness according to a fifth embodiment. Fig. 13 is a diagram for explaining the characteristics of a filter unit provided in the wire harness shown in Fig. 12. Fig. 14 is a diagram showing a configuration example of an in-vehicle device according to a sixth embodiment.

[0010] The connector system described in Patent Document 1 is an excellent system in terms of ensuring security. However, because the processing unit, verification unit, and control unit are realized by electronic devices, and the electronic devices and switches are built into the connector, it is difficult to simplify the configuration. As a result, manufacturing costs tend to be high.

[0011] The present disclosure has been made to solve the above-mentioned problems, and one object of the present disclosure is to provide a wire harness, a harness identification system, and an on-board device that contribute to improving communication security with a simple configuration.

[0012] Effect of the Present Disclosure According to the present disclosure, it is possible to provide a wire harness, a harness identification system, and an in-vehicle device that contribute to improving communication security with a simple configuration.

[0013] [Description of Embodiments of the Present Disclosure] Preferred embodiments of the present disclosure will be listed and described below. At least some of the embodiments described below may be combined in any combination.

[0014] (1) A wire harness according to a first aspect of the present disclosure is a wire harness that connects communication between a first communication unit and a second communication unit, and includes: a transmission line that is provided between the first communication unit and the second communication unit and transmits a signal from at least one of the first communication unit and the second communication unit; and a filter unit that is provided at a predetermined position on the transmission line and has predetermined characteristics.

[0015] A filter unit having predetermined characteristics is provided at a predetermined position on the transmission line. For example, when a diagnostic signal is transmitted to the transmission line, a signal corresponding to the characteristics of the filter unit is generated. On the other hand, a wire harness without a filter unit does not generate such a signal. Therefore, it is possible to determine whether the connected wire harness is a genuine wire harness based on whether a signal corresponding to the characteristics of the filter unit is included in the reflected waveform of the diagnostic signal. That is, it is possible to determine the authenticity of the connected wire harness. This makes it possible to detect that a genuine wire harness is not connected (that an unauthorized wire harness has been connected). By stopping (blocking) communication when it is detected that an unauthorized wire harness has been connected, it is possible to prevent communication with unintended devices. This makes it possible to prevent hacking or data tampering of in-vehicle devices. Thus, the wire harness of the present disclosure can contribute to improving communication security with a simple configuration.

[0016] (2) In the above (1), the filter unit may be configured to filter out-of-band signals that are outside the communication band used for communication between the first communication unit and the second communication unit. This allows the filter unit to be provided on the communication transmission line, thereby further simplifying the configuration.

[0017] (3) In the above (1), the transmission line may include a line that is not used for communication between the first communication unit and the second communication unit. A transmission line for identifying whether the wire harness is genuine is provided separately from the transmission line for communication. This allows the characteristics of the filter unit to be set without being limited by the communication band, thereby increasing design freedom.

[0018] (4) In any of the above (1) to (3), the filter section may include an open stub having a predetermined length, and the predetermined characteristic may include a capacitive reflection characteristic. This makes it possible to easily form a filter section having the predetermined characteristic.

[0019] (5) In any one of (1) to (3) above, the filter unit may include a plurality of open stubs having a predetermined length, and the plurality of open stubs may be provided at predetermined positions on the transmission line. This allows the authenticity of the wire harness to be determined based on a plurality of signals, thereby improving the accuracy of the determination.

[0020] (6) In the above (5), the lengths of the plurality of open stubs may be different from each other. This allows the patterns of the plurality of signals to be changed, and therefore makes it easy to change the detection pattern for authenticity determination.

[0021] (7) In any of the above (1) to (3), the filter section may be configured to have predetermined characteristics by varying the line width of the transmission line. This makes it easy to form the filter section, and therefore, reduces manufacturing costs.

[0022] (8) In the above (7), the filter portion may include a filter region having an inductive reflection characteristic or a filter region having a capacitive reflection characteristic. When the filter portion includes a filter region having an inductive reflection characteristic, the filter region having an inductive reflection characteristic can be formed, for example, by making the line width of the transmission line smaller than the line width of a region other than the region where the filter portion is provided. This makes it possible to easily obtain a wire harness that contributes to improving communication security with a simple configuration.

[0023] On the other hand, when the filter portion includes a filter region having capacitive reflection characteristics, the filter region having capacitive reflection characteristics can be formed, for example, by making the line width of the transmission line larger than the line width of the region other than the region where the filter portion is provided. Therefore, this also makes it possible to easily obtain a wire harness that contributes to improving communication security with a simple configuration.

[0024] (9) In any of the above (1) to (8), the filter unit may include a plurality of filters having different reflection characteristics, thereby enabling a simple configuration to detect that a genuine wire harness is not connected (that an unauthorized wire harness is connected).

[0025] (10) In the above (9), the filter unit may be configured to be provided at a predetermined position on the transmission line. This makes it possible to determine whether the wire harness is genuine or not based on information about the position at which the filter unit is provided.

[0026] (11) In the above (10), the wire harness may further include a connector provided at an end of the transmission line, and the filter portion may be located inside the connector. This reduces the difference in appearance between the presence and absence of the filter portion. That is, it is possible to make it difficult to tell from the outside that a filter portion is provided.

[0027] (12) In the above (11), the wire harness may further include a sheet-like holding member for holding the transmission line, which makes it easier to form a filter portion having predetermined characteristics.

[0028] (13) A harness identification system according to a second aspect of the present disclosure includes a wire harness and an identification device that identifies whether the wire harness is genuine. The wire harness includes a transmission line that transmits a signal and a filter unit that is provided at a predetermined position on the transmission line and has predetermined characteristics. The identification device includes a signal transmitter that transmits an identification signal to the transmission line, a signal receiver that receives a reflected waveform of the identification signal, and an identification unit that identifies the authenticity of the wire harness based on whether the received reflected waveform includes a signal with predetermined characteristics generated by the filter unit. This makes it possible to detect whether a genuine wire harness is connected (i.e., whether an unauthorized wire harness is connected). By stopping communication when it is detected that an unauthorized wire harness is connected, communication with unintended devices can be prevented. Therefore, a simple configuration can contribute to improving communication security.

[0029] (14) An on-board device according to a third aspect of the present disclosure is an on-board device mounted on a vehicle, and includes a connector to which a wire harness is connected, a substrate on which electronic components are mounted, a transmission line for transmitting signals between the electronic components and the wire harness, and a filter unit having predetermined characteristics and provided at a predetermined position on the transmission line. This can contribute to improving communication security with a simple configuration.

[0030] [Details of the embodiments of the present disclosure] Specific examples of a wire harness, a harness identification system, or an on-vehicle device according to the embodiments of the present disclosure will be described below with reference to the drawings. Note that in the following embodiments, the same components are assigned the same reference numerals. Their functions and names are also the same. Therefore, detailed description thereof will not be repeated.

[0031] 1, a harness identification system 50 according to this embodiment includes an identification device 100 that identifies whether a connected wire harness is genuine, and a wire harness 200 that connects devices for communication. The harness identification system 50 is mounted on, for example, a vehicle 30. The vehicle 30 is equipped with various on-board devices including a first on-board device 60 and a second on-board device 70.

[0032] The first in-vehicle device 60 includes a first communication unit 62. The second in-vehicle device 70 includes a second communication unit 72. The wire harness 200 connects communication between the first communication unit 62 and the second communication unit 72. The wire harness 200 may be directly connected to the first communication unit 62 and the second communication unit 72, or may be indirectly connected to them via another wire harness or the like.

[0033] The identification device 100 is provided in the first in-vehicle device 60. However, the present invention is not limited to this configuration. The identification device 100 may be provided in the second in-vehicle device 70, or may be provided in both the first in-vehicle device 60 and the second in-vehicle device 70.

[0034] Some ECUs, a type of in-vehicle device, have a cable fault diagnosis function that uses TDR (Time Domain Reflectometry). TDR is a method of measuring changes in the characteristic impedance of a transmission line by sending a pulse signal or step signal to the object being measured and observing the reflected waveform that returns. By observing the change in characteristic impedance, cable faults such as breaks can be detected.

[0035] The first in-vehicle device 60 is an ECU having such a function, and the identification device 100 uses this diagnostic function to identify whether or not the connected wire harness is the genuine wire harness 200. In other words, the identification device 100 uses the diagnostic function of the ECU not for fault diagnosis but for identifying (authenticating) whether or not the wire harness is the genuine wire harness 200.

[0036] When the first in-vehicle device 60 and the second in-vehicle device 70 are ECUs, the first communication unit 62 and the second communication unit 72 include a PHY (Physical Layer). The PHY acts as an intermediary between a microcontroller included in the ECU and a communication medium.

[0037] 2 , the wire harness 200 according to the present embodiment includes an electric wire portion 210, a first connector 220 provided at a first end, which is one end of the electric wire portion 210, a second connector 230 provided at a second end, which is the other end of the electric wire portion 210, and a filter portion 240 having predetermined characteristics. The electric wire portion 210 is, for example, a wire or a cable, and includes a transmission line 212 that transmits a signal. The transmission line 212 is covered with an insulating material. The filter portion 240 is provided at a predetermined position on the transmission line 212. In the present embodiment, the filter portion 240 is provided at a position on the transmission line 212 outside the connector.

[0038] The filter unit 240 includes a filter that has a cutoff characteristic for a predetermined frequency. As described above, the identification device 100 uses the characteristic of the filter unit 240 to authenticate (identify) the wire harness 200. Specifically, whether the connected wire harness is the wire harness 200 is identified based on whether a reflection (reflected signal) by the filter unit 240 is included in the reflected waveform obtained by the TDR method.

[0039] More specifically, the filter unit 240 provided on the transmission line 212 includes a reflection (reflected signal) according to the characteristics of the filter unit 240 in the reflected waveform of the input pulse signal or step signal (also referred to as an "identification signal" or an "input signal") in a predetermined frequency band. Therefore, whether or not there is a reflection according to the characteristics of the filter unit 240 determines whether or not the connected wire harness is the wire harness 200. That is, the detection information of the filter unit 240 is used to identify the wire harness 200. Therefore, whether or not a signal generated by the characteristics of the filter unit 240 is detected can be used to identify whether or not the connected wire harness is the genuine wire harness 200 or an unauthorized wire harness different from the wire harness 200.

[0040] 3A and 3B, the filter section 240 includes an open stub 242. FIG. 3A shows an example of an open stub. FIG. 3B shows the frequency characteristics of the open stub. The horizontal axis of FIG. 3B represents frequency, and the vertical axis represents transmission loss. Referring to FIG. 3B, the open stub 242 functions as a filter circuit that attenuates only a specific band (resonant frequency f) to a very low level. In other words, the open stub 242 functions as a band reject filter that exhibits short-circuit characteristics at the resonant frequency f.

[0041] The resonant frequency f is controlled by the length (electrical length) a of the open stub 242, and its bandwidth is controlled by the width b of the open stub 242. The shape (length a and width b) of the open stub 242 is set so that the resonant frequency f is located within a predetermined band. In this embodiment, the shape of the open stub 242 is set so that the resonant frequency f is located outside the communication band. As a result, the open stub 242 functions as a filter having cutoff characteristics outside the communication band. The filter unit 240 configured in this manner can also be referred to as an out-of-band signal filter unit that filters signals outside the communication band. Note that in this disclosure, the "communication band" refers to a frequency band used for communication between devices, and is a band that satisfies the frequency characteristics of a standard such as IEEE 802.3 (registered trademark). Because the open stub 242 functions as a filter having characteristics outside the communication band, providing the open stub 242 on the transmission line 212 does not affect the quality of the communication signal (signal in the communication band).

[0042] FIG. 4 is a graph showing an example of the reflection characteristics of the filter section 240 (open stub 242). FIG. 4 shows an example of a reflected waveform of the transmission line 212 obtained by the TDR method. The horizontal axis of FIG. 4 represents time, and the vertical axis represents the impedance of the reflected waveform (Reflection Waveform Impedance, simply indicated as "Reflection" on the graph). Referring to FIG. 4, when the open stub 242 is provided on the transmission line 212, the open stub 242 exhibits capacitive reflection characteristics. The portion where the open stub 242 is provided has lower impedance than other portions. The reflection characteristics of the open stub 242 are such that the depth of reflection is controlled by the length a of the open stub 242 ( FIG. 3A ), and the time width is controlled by the width b of the open stub 242 ( FIG. 3A ). In this case, the frequency band of the input signal used in the TDR method can be a frequency band outside the communication band.

[0043] [Identification Device 100] Referring to Fig. 5, the identification device 100 is provided in the first in-vehicle device 60 as described above. Referring to Fig. 6, the identification device 100 includes a control unit 110, a communication unit 120, and a memory 130. The control unit 110 includes a computing element (processor) such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit 110 includes, as a functional unit, an identification unit 112 that identifies whether a wire harness is a genuine wire harness by the TDR method.

[0044] The communication unit 120 includes a signal transmitting unit 122 and a signal receiving unit 124. The signal transmitting unit 122 transmits an identification signal (input signal) to the transmission line of the wire harness under the control of the control unit 110. The signal receiving unit 124 receives a reflected waveform returned from the transmission line of the wire harness and provides the reflected waveform to the identification unit 112. The memory 130 includes a non-volatile memory such as a flash memory. The memory 130 stores software (computer programs) executed by the control unit 110 (identification unit 112) and various information (data). The memory 130 also stores identification information for determining whether the reflected waveform includes a reflection (reflected signal) corresponding to the characteristics of the filter unit 240 (open stub 242). The identification information includes, for example, characteristic information of the filter unit 240 (open stub 242). Specifically, the identification information includes at least one of the resonant frequency of the open stub 242, its bandwidth, reflection characteristics (reflection depth, etc.), and position information where the open stub 242 is formed.

[0045] The identification unit 112 has a function of observing the input reflected waveform. The identification unit 112 refers to the identification information stored in the memory 130 and determines whether the input reflected waveform includes a waveform (waveform signal) generated by the filter unit 240 (open stub 242). Based on the determination result, the identification unit 112 identifies whether the wire harness is genuine or not. In other words, the identification unit 112 determines whether the wire harness is authentic.

[0046] 2, since the wire harness 200 includes the filter unit 240, when the wire harness 200 is connected, the identification unit 112 determines that the wire harness is genuine, i.e., "true." On the other hand, when a wire harness other than the wire harness 200 is connected, the identification unit 112 determines that the wire harness is not genuine, i.e., "false." The identification unit 112 outputs the determination result (true / false result) to the ECU (first in-vehicle device 60). When the true / false result is "false," the ECU cuts off communication.

[0047] Such authentication processing (identification processing) may be configured to be performed continuously, or may be configured to be performed periodically or irregularly. If performed irregularly, the processing may be triggered by some event, or may be configured to be performed according to a preset schedule.

[0048] 6, the signal transmitting unit 122 of the identification device 100 transmits an identification signal (input signal) to the transmission line. The signal receiving unit 124 of the identification device 100 receives a reflected signal (reflected waveform) of the identification signal transmitted by the signal transmitting unit 122.

[0049] 3A, 3B, and 4, the input signal is filtered by the filter section 240 (open stub 242). Therefore, the reflected waveform includes a reflection (reflected signal) according to the characteristics (shape) of the open stub 242.

[0050] 6 , the identification device 100 references the information (identification information) in the memory 130 to determine whether the reflected waveform received via the signal receiving unit 124 includes a reflection generated by the filter unit 240. Based on the determination result, the identification device 100 identifies whether the connected wire harness is genuine. The identification device 100 transmits an authenticity result to the ECU, and if the authenticity result is "false," the ECU cuts off communication.

[0051] The identification unit 112 may be configured to output a determination result (true / false result) only when the result is "false." For example, the identification unit 112 may be configured to output a signal (for example, a detection signal or a communication cutoff signal) to notify the user of an unauthorized connection of a wire harness only when the identification unit 112 detects the connection of an unauthorized wire harness.

[0052] In the wire harness 200 according to the present embodiment, a filter unit 240 having predetermined characteristics is provided at a predetermined position on the transmission line 212. By transmitting a diagnostic signal to the transmission line 212, a signal (reflection) corresponding to the characteristics of the filter unit 240 is generated. On the other hand, a wire harness not provided with the filter unit 240 does not generate such a signal (reflection corresponding to the filter characteristics). Therefore, based on whether or not the reflected waveform of the diagnostic signal includes a signal (reflection) corresponding to the characteristics of the filter unit 240, it is possible to determine whether the connected wire harness is genuine or not. In other words, it is possible to determine the authenticity of the connected wire harness. This makes it possible to detect that the genuine wire harness 200 is not connected (that an unauthorized wire harness has been connected). By cutting off communication when it is detected that an unauthorized wire harness has been connected, it is possible to prevent communication with unintended devices. This makes it possible to prevent hacking or data tampering of in-vehicle devices. As described above, the wire harness 200 according to the present embodiment can contribute to improving communication security with a simple configuration.

[0053] The filter unit 240 filters out signals outside the communication band that is outside the communication band used for communication between the first communication unit 62 and the second communication unit 72. This allows the filter unit 240 to be provided on the communication transmission line 212, thereby simplifying the configuration.

[0054] The filter portion 240 includes an open stub 242 having a predetermined length. In this case, the characteristic of the filter portion 240 is a capacitive reflection characteristic. This makes it easy to form a filter portion 240 having a predetermined characteristic. By storing information on the capacitive reflection characteristic as identification information, it becomes easier to determine whether the wire harness is genuine or not.

[0055] 7 , a wire harness 250 according to the present embodiment differs from the first embodiment in that it includes a plurality of open stubs. In the wire harness 250, a filter section 260 is provided on a transmission line 212. The filter section 260 includes a plurality of open stubs having a predetermined length.

[0056] FIG. 7 shows an example configuration in which four open stubs 262, 264, 266, and 268 are provided. However, the number of open stubs is not limited to four and may be two, three, five, or more. The open stubs 262, 264, 266, and 268 are each provided at a predetermined position. Since the position information of the open stubs can also be obtained by analyzing the reflected waveform using the TDR method, the position information of the open stubs can also be used for authenticating the wire harness. The position information can be the distance from a reference point. Furthermore, the position information can also be the spacing between the open stubs. The spacing between the open stubs may be equal or may be unequal.

[0057] The open stubs 262, 264, 266, and 268 have different lengths (electrical lengths). Because the depth of reflection is controlled by the length of the open stubs, the reflected waveforms at the portions where the open stubs 262, 264, 266, and 268 are formed have different reflection depths. Note that the horizontal axis of Figure 7 represents time, and the vertical axis represents the impedance of the reflected waveform.

[0058] When multiple open stubs 262, 264, 266, and 268 are arranged in a barcode pattern as shown in FIG. 7 , the magnitude (depth) of reflection may be divided into several levels (classes), and the depth of reflection may be divided into levels. For example, if the magnitude (depth) of reflection is divided into five levels, the reflection of open stub 266, which has the longest electrical length, may be designated as [0], the reflections of open stubs 262, 264, and 268 may be designated as [3], [2], and [1], respectively, and the reflection at a position where no open stub is provided may be designated as [4]. By dividing the depth of reflections caused by open stubs 262, 264, 266, and 268 into levels in this way, it becomes possible to use the detection information of filter section 260 as numerical information (an identification code: e.g., [3, 2, 0, 4, 1]). The numerical information (identification code) can be changed by changing the number, length, and order of the open stubs.

[0059] As described above, in wire harness 250 according to the present embodiment, filter section 260 includes a plurality of open stubs 262, 264, 266, and 268 having predetermined lengths, and the plurality of open stubs 262, 264, 266, and 268 are provided at predetermined positions on transmission line 212. This allows the authenticity of the wire harness to be determined based on a plurality of signals, thereby improving the accuracy of the determination.

[0060] Furthermore, by making the lengths of the plurality of open stubs 262, 264, 266, and 268 different from one another, it is possible to change the appearance pattern of the plurality of signals, thereby easily changing the detection pattern for authenticity determination.

[0061] The open stubs may have the same length (electrical length).Furthermore, the open stubs may include open stubs with the same length (electrical length).

[0062] The other configurations and effects are the same as those of the first embodiment.

[0063] Third Embodiment Referring to Fig. 8, a harness identification system according to the present embodiment includes a wire harness 300 instead of the wire harness 200 (see Fig. 2). The wire harness 300 includes an electric wire portion 310 instead of the electric wire portion 210 (see Fig. 2). The electric wire portion 310 includes a transmission line 212. The transmission line 212 is provided with a filter portion 320 instead of the filter portion 240 (see Fig. 2). In this respect, the present embodiment differs from the first or second embodiment.

[0064] 9A and 9B , filter section 320 includes a filter (filter region) having predetermined characteristics that is provided at a predetermined position on transmission line 212. Filter section 320 (filter region) is configured to have the predetermined characteristics by changing (varying) the shape of transmission line 212. Specifically, filter section 320 includes a filter region (filter 322: FIG. 9A ) formed by thickening transmission line 212, or a filter region (filter 324: FIG. 9B ) formed by thinning transmission line 212.

[0065] 9A , the line width W and length L of the filter 322 are set so as to have predetermined characteristics. The line width W is set to a value larger than the values ​​of the area of ​​the transmission line 212 other than the area where the filter section 320 is provided. The filter 322 exhibits capacitive reflection characteristics when measured by the TDR method. The line width W controls the magnitude (lowness) of the reflection, and the length L controls the time width of the reflection.

[0066] 9B , the line width W and length L of the filter 324 are also set so as to have predetermined characteristics. The line width W is set to a value smaller than that of the region of the transmission line 212 other than the region where the filter section 320 is provided. The filter 324 exhibits inductive reflection characteristics when measured by the TDR method. The line width W controls the magnitude (height) of the reflection, and the length L controls the time width of the reflection.

[0067] The shape of the filter is set so that the resonant frequency is located outside the communication band, similar to the first embodiment, i.e., the filter section 320 is formed so as to filter signals outside the communication band.

[0068] When the transmission line 212 is a wire, the above-described filter can be formed by partially changing the thickness of the transmission line 212. When the transmission line 212 is formed on, for example, a printed circuit board, the above-described filter can be formed by patterning a conductive layer.

[0069] The filter section 320 may be configured to include either one of the filters 322 and 324, or may be configured to include both. The filter section 320 may further be configured to include a plurality of either the filters 322 or the filters 324.

[0070] When the filter section 320 includes both the filter 322 and the filter 324, at least some of the filters may have different shapes. An example of such a configuration of the filter section 320 is shown in FIG.

[0071] 10 , for example, filter section 320 includes filters 330, 332, 334, and 336 formed on transmission line 212. The number of filters formed is not limited to four, and may be two, three, five, or more. Note that the horizontal axis of FIG. 10 represents time, and the vertical axis represents the impedance of the reflected waveform.

[0072] Filters 332 and 336 are classified into the group of filter 322 shown in Fig. 9A. Filters 330 and 334 are classified into the group of filter 324 shown in Fig. 9B. When transmission line 212 on which filter section 320 is formed is measured by the TDR method, capacitive reflections (lower impedance than transmission line 212) are observed at locations thicker than transmission line 212 (locations of filters 332 and 336), and inductive reflections (higher impedance than transmission line 212) are observed at locations thinner than transmission line 212 (locations of filters 330 and 334). These can be used as information on the location (position) and the level of impedance, just as in the case where an open stub is provided.

[0073] As in the second embodiment, when multiple filters 330, 332, 334, and 336 are provided on the transmission line 212, the magnitude (high / low) of reflection may be divided into several levels (classes), and the reflection levels may be classified according to the levels. For example, if the magnitude (high / low) of reflection is divided into five levels, the reflections of filters 332 and 336 may be classified as [0] and [1], respectively, the reflections of positions (transmission line 212) where no filters are provided may be classified as [2], and the reflections of filters 330 and 334 may be classified as [3] and [4], respectively. By classifying the reflections caused by filters 330, 332, 334, and 336 into levels, the detection information of the filter unit 320 can be used as numerical information (identification code: e.g., [3, 2, 0, 4, 1]). The numerical information (identification code) can be changed by changing the number, shape, and order of the filters.

[0074] In this embodiment, as described above, the filter section 320 is configured to have predetermined characteristics by varying the line width of the transmission line 212. This makes it easy to form the filter section 320, and therefore, makes it easy to reduce manufacturing costs.

[0075] The filter section 320 may be configured to include a filter region (filter 324) having inductive reflection characteristics, in which the line width of the transmission line 212 is smaller than the line width of the transmission line 212 other than the region where the filter section 320 is provided. In this case, a wire harness that contributes to improving communication security can be easily obtained with a simple configuration.

[0076] The filter section 320 may further include a filter region (filter 322) having capacitive reflection characteristics, in which the line width of the transmission line 212 is larger than the line width of the transmission line 212 other than the region where the filter section 320 is provided. In this case, too, a wire harness that contributes to improving communication security can be easily obtained with a simple configuration.

[0077] The other configurations and effects are the same as those of the first or second embodiment.

[0078] 11 , a wire harness 400 according to the present embodiment differs from the first to third embodiments in that a filter portion 420 is located inside a connector. The wire harness 400 includes an electric wire portion 410. The electric wire portion 410 includes a transmission line 212. The filter portion 420 is provided on the transmission line 212. The filter portion 420 may have the same configuration as the filter portion shown in the first to third embodiments.

[0079] In the present embodiment, filter unit 420 is formed so as to be located inside first connector 220. However, filter unit 420 may also be formed so as to be located inside second connector 230. Furthermore, a filter unit other than filter unit 420 may be added, and the added filter unit may be located inside second connector 230. In other words, a configuration may be adopted in which filter units are provided in both first connector 220 and second connector 230.

[0080] In this way, the filter portion 420 of the wire harness 400 is configured to be located inside the connector. That is, the filter portion 420 is built into the connector. This reduces the difference in appearance between the presence and absence of the filter portion 420. That is, it is possible to make it difficult to tell from the outside that the filter portion 420 is provided. Even with this configuration, the configuration can be simplified compared to when the electronic device is built into the connector.

[0081] 12 , a wire harness 500 according to the present embodiment includes a flat cable 510 as an electric wire portion. The flat cable 510 is a flat cable such as a flexible printed circuit (FPC) and includes a plurality of electric wires.

[0082] The flat cable 510 includes a communication transmission line 214 and an identification transmission line 216 that is not used for communication. The communication transmission line 214 is a line (electrical wire) used for communication between the first communication unit 62 ( FIG. 1 ) and the second communication unit 72 ( FIG. 1 ). The identification transmission line 216 is a line (electrical wire) dedicated to identification and not used for communication between the first communication unit 62 ( FIG. 1 ) and the second communication unit 72 ( FIG. 1 ). The identification transmission line 216 is provided with a filter unit 520. The filter unit 520 includes multiple open stubs. In this embodiment, since the filter unit 520 is provided on the identification transmission line 216, the characteristics of the filter unit 520 are not limited to a frequency band. Referring to FIG. 13 , the filter unit 520 can be configured, for example, so that the resonant frequency f is located within the communication band.

[0083] The communication transmission line 214 and the identification transmission line 216 are formed of a conductive layer. The flat cable 510 includes a base film 512 on which the communication transmission line 214 and the identification transmission line 216 are formed, and a cover film 514 that covers the communication transmission line 214 and the identification transmission line 216. The base film 512 and the cover film 514 are sheet-like holding members that hold the communication transmission line 214 and the identification transmission line 216. The base film 512 and the cover film 514 are made of flexible insulating films (sheets).

[0084] The flat cable 510 may be configured to include other electric wires in addition to the communication transmission line 214 and the identification transmission line 216. Furthermore, the number of layers on which the transmission lines are formed is not limited to one, and multiple layers may be stacked. By using such a flat cable 510 as the electric wire section, when providing the filter section 520 on the transmission line, the filter section 520 can be easily processed and positional accuracy can be achieved.

[0085] The wire harness 500 according to the present embodiment includes a sheet-like holding member that holds the transmission line, and therefore, it is easy to form the filter portion 520 having predetermined characteristics.

[0086] As a wire harness using a flat cable, an assembly harness such as e-STEALTH (registered trademark) is known. The wire harness 500 according to the present embodiment can also be configured using such an assembly harness.

[0087] 12, the connector is omitted. As shown in the fourth embodiment, the filter unit 520 may be provided inside the connector. Furthermore, at least some of the open stubs constituting the filter unit 520 may be replaced with the filters shown in the third embodiment.

[0088] In this embodiment, an example has been shown in which the flat cable 510 is provided with the identification transmission line 216 that is not used for communication. However, the present disclosure is not limited to such an embodiment. The flat cable may be configured not to include the identification transmission line 216 that is not used for communication. In this case, the above-described filter section may be provided on the transmission line for communication.

[0089] 14 , an in-vehicle device 600 according to this embodiment includes a filter unit 610 similar to a filter unit provided in a wire harness. That is, an identification filter unit 610 is provided in the in-vehicle device 600. However, this filter unit 610 is not intended to identify the wire harness, but rather to identify the in-vehicle device. Specifically, the filter unit 610 is used to identify whether the in-vehicle device connected to the wire harness is a genuine in-vehicle device 600.

[0090] The in-vehicle device 600 includes a connector 620 to which the wire harness is connected, a substrate 630 on which electronic components are mounted, a transmission line 640 that transmits signals between the electronic components and the wire harness, and the above-mentioned filter section 610 that is provided at a predetermined position on the transmission line 640 and has predetermined characteristics.

[0091] Substrate 630 is a printed circuit board (mounting board) on which electronic components are mounted. FIG. 14 shows an example in which electronic components 650, 652, 654, and 656 are mounted on substrate 630 as electronic components. Connector 620 includes terminal portion 622. Terminal portion 622 of connector 620 is electrically connected to a transmission line of the wire harness. Substrate 630 is provided with transmission line 640 for electrically connecting mounted electronic components 650, 652, 654, and 656 to terminal portion 622 of connector 620. Filter portion 610 is provided at a predetermined position on transmission line 640. Filter portion 610 may be provided on substrate 630 or may be provided so as to be located inside connector 620.

[0092] The filter unit 610 may have the same configuration as the filter unit described in the above embodiment. In this case, the identification device 100 (see FIG. 6) is provided in, for example, a device that communicates with the in-vehicle device 600. This makes it possible to detect the connection of an unauthorized device when a wire harness connected to the in-vehicle device 600 is removed and another device is connected to the wire harness.

[0093] In the above embodiment, an example has been shown in which the identification device is provided in an ECU and the diagnostic function of the ECU is used to identify a wire harness or an on-board device. However, the present disclosure is not limited to such an embodiment. The identification device may be configured not to use the diagnostic function of the ECU. The identification device may be configured to be installed in a vehicle as a dedicated on-board device used to identify a wire harness or an on-board device.

[0094] In the above-described embodiments, filter units may be provided at multiple locations in the wire harness. Similarly, filter units may be provided at multiple locations in the on-vehicle device. Furthermore, in the above-described first to fourth embodiments, a transmission line for identification that is not used for communication may be provided in the wire harness, and a filter unit may be provided on the transmission line for identification.

[0095] In the above embodiment, an example has been shown in which a wire harness or an on-board device is identified using the TDR method, but the present disclosure is not limited to such an embodiment. As long as it is possible to identify a wire harness or an on-board device based on the presence or absence of a filter portion, a method other than the TDR method may be used.

[0096] In the above embodiment, an example was shown in which the filter unit is configured to have characteristics outside the communication band, but the present disclosure is not limited to such an embodiment. The filter unit may also be configured to have characteristics within the communication band. For example, the filter unit may be configured so that at least a portion of the resonant frequency band of the filter unit is included in the communication band. Even if the band of frequency characteristics created by the line width or stub of the transmission line overlaps part of the frequency band used for communication, there is no particular problem as long as there is no distortion of the communication waveform or signal error. In other words, some impedance mismatch is acceptable as long as it is within a range that does not affect the communication signal quality (tolerance range).

[0097] The filter section may have a configuration other than that shown in the above embodiment. For example, the filter section may be configured using electronic components such as a capacitor.

[0098] Embodiments obtained by appropriately combining the techniques disclosed above are also included within the technical scope of the present disclosure.

[0099] The embodiments disclosed herein are merely examples, and the present disclosure is not limited to the above-described embodiments. The scope of the present disclosure is defined by the claims in the scope of the claims, taking into consideration the description of the detailed description of the invention, and includes all modifications within the meaning and scope equivalent to the wordings described therein.

[0100] 30 Vehicle 50 Harness identification system 60 First on-board device 62 First communication unit 70 Second on-board device 72 Second communication unit 100 Identification device 110 Control unit 112 Identification unit 120 Communication unit 122 Signal transmission unit 124 Signal reception unit 130 Memory 200, 250, 300, 400, 500 Wire harness 210, 310, 410 Electric wire unit 212, 214, 216, 640 Transmission line 220 First connector 230 Second connector 240, 260, 320, 420, 520, 610 Filter unit 242, 262, 264, 266, 268 Open stub 322, 324, 330, 332, 334, 336 Filter 510 Flat cable 512 Base film 514 Cover film 600 In-vehicle device 620 Connector 622 Terminal portion 630 Substrate 650, 652, 654, 656 Electronic component

Claims

1. A wire harness that connects communication between a first communication unit and a second communication unit, a transmission line provided between the first communication unit and the second communication unit, for transmitting a signal from at least one of the first communication unit and the second communication unit; a filter portion provided at a predetermined position on the transmission line and having predetermined characteristics.

2. The wire harness according to claim 1 , wherein the filter unit filters out signals outside a communication band that is outside a communication band used for communication between the first communication unit and the second communication unit.

3. The wire harness according to claim 1 , wherein the transmission line includes a line that is not used for communication between the first communication unit and the second communication unit.

4. the filter section includes an open stub having a predetermined length; The wire harness according to claim 1 , wherein the predetermined characteristic includes a capacitive reflection characteristic.

5. the filter section includes a plurality of open stubs having a predetermined length; The wire harness according to claim 1 , wherein the plurality of open stubs are provided at predetermined positions on the transmission line.

6. The wire harness according to claim 5 , wherein the open stubs have lengths different from one another.

7. 4. The wire harness according to claim 1, wherein the filter portion is configured to have the predetermined characteristic by varying a line width of the transmission line.

8. The wire harness according to claim 7 , wherein the filter portion includes a filter region having an inductive reflection characteristic or a filter region having a capacitive reflection characteristic.

9. The wire harness according to claim 1 , wherein the filter portion includes a plurality of filters having different reflection characteristics.

10. The wire harness according to claim 1 , wherein the filter portion is provided at a predetermined position on the transmission line.

11. a connector provided at an end of the transmission line; The wire harness according to claim 10 , wherein the filter portion is located inside the connector.

12. The wire harness according to claim 1 , further comprising a sheet-like holding member that holds the transmission line.

13. A wire harness, an identification device for identifying whether the wire harness is genuine, The wire harness includes: a transmission line for transmitting a signal; a filter section provided at a predetermined position on the transmission line and having predetermined characteristics; The identification device a signal transmitting unit that transmits an identification signal to the transmission line; a signal receiving unit that receives a reflected waveform of the identification signal; an identification unit that identifies the authenticity of the wire harness based on whether or not the received reflected waveform includes a signal with the predetermined characteristics generated by the filter unit.

14. An in-vehicle device mounted on a vehicle, a connector to which the wire harness is connected; a substrate on which electronic components are mounted; a transmission line for transmitting a signal between the electronic component and the wire harness; a filter section provided at a predetermined position on the transmission line and having predetermined characteristics.