Control device, method for identifying abnormal parts, and computer program

Abstract

To enable the identification of abnormal parts in the signal lines. [Solution] The control device 30 is connected to the electronic device 10 via a signal line 20. The control device 30 transmits an abnormal location identification signal to the electronic device 10 via the signal line 20. In response to detecting a reflected signal of the abnormal location identification signal, the control device 30 calculates the reflection time from the time the abnormal location identification signal is transmitted until the reflected signal is received, and identifies the abnormal location on the signal line 20 based on the reflection time.

Description

Technical Field

[0001] The present invention relates to a control device, an abnormal part identification method, and a computer program.

Background Art

[0002] In Patent Document 1, as a conventional cable fault diagnosis device, the voltage of a transmission signal excited by a communication terminal connected to a cable and the voltage of a reflected signal returned through a network cable are detected, and the detected voltage values are partitioned by a plurality of preset threshold values. A device configured to automatically determine the fault state of the network cable from the results is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, although the above-described conventional cable fault diagnosis device can diagnose whether a cable is faulty or not, it cannot identify the part (abnormal part) where the fault has occurred.

[0005] The present invention has been made paying attention to such problems, and an object thereof is to be able to identify an abnormal part of a signal line such as a cable.

Means for Solving the Problems

[0006] To solve the above problems, a control device connected to an electronic device via a signal line according to one aspect of the present invention is configured to transmit an abnormal location identification signal to the electronic device via the signal line, and in response to the detection of a reflected signal of the abnormal location identification signal, calculate the reflection time from the transmission of the abnormal location identification signal to the reception of the reflected signal, and identify the abnormal location of the signal line based on the reflection time.

[0007] Furthermore, according to one aspect of the present invention, a method for identifying an abnormal location in a signal line by a control device connected to an electronic device via a signal line involves transmitting an abnormal location identification signal to the electronic device via the signal line, and in response to detecting a reflected signal of the abnormal location identification signal, calculating the reflection time from the transmission of the abnormal location identification signal to the reception of the reflected signal, and identifying the abnormal location in the signal line based on the reflection time.

[0008] Furthermore, a computer program for a control device connected to an electronic device via a signal line, according to one aspect of the present invention, causes the control device to transmit an abnormal location identification signal to the electronic device via the signal line, and in response to detecting a reflected signal of the abnormal location identification signal, calculates the reflection time from the transmission of the abnormal location identification signal to the reception of the reflected signal, and identifies the abnormal location of the signal line based on the reflection time. [Effects of the Invention]

[0009] According to these embodiments of the present invention, it is possible to identify abnormal parts of a signal line. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a control system according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view of a signal line according to one embodiment of the present invention. [Figure 3] This diagram illustrates a method for detecting reflected signals from abnormal area identification signals. [Figure 4] This figure shows a table for identifying abnormal areas, illustrating the relationship between reflection time T and line length X. [Figure 5]This is a flowchart illustrating the process for identifying abnormal parts according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, similar components will be given the same reference numerals.

[0012] Figure 1 is a schematic diagram of a control system 1 according to one embodiment of the present invention.

[0013] The control system 1 comprises an electronic device 10, a signal line 20, and a control device 30. In this embodiment, the control system 1 is described using an Advanced Driver Assistance System (ADAS) installed in a vehicle as an example, but of course, the control system 100 is not limited to an Advanced Driver Assistance System. Other examples of the control system 100 include, for example, a monitoring system for a factory.

[0014] The electronic device 10 is a device having at least one of the following functions: acquiring data and transmitting said data to the control device 30 via the signal line 20, and outputting the data received from the control device 30 via the signal line 20. Examples include cameras, displays, and audio equipment. The electronic device 10 according to this embodiment is an in-vehicle camera that constitutes part of an advanced driver assistance system.

[0015] The signal line 20 is composed of one or more cables having a predetermined characteristic impedance, and transmits signals by connecting the electronic device 10 and the control device 30. The signal line 20 according to this embodiment is composed of multiple coaxial cables connected together, each having an inner conductor 21, an insulator 22 surrounding the inner conductor 21, an outer conductor 23 surrounding the insulator 22, and an outer covering 24 surrounding the outer conductor 23, as shown in the cross-sectional view of Figure 2.

[0016] The characteristic impedance of the signal line 20 depends on its internal structure, such as the outer diameter of the inner conductor 21 and the inner diameter of the outer conductor 23. Therefore, if the signal line 20 is bent or otherwise crushed (compressed) in part, the outer diameter of the inner conductor 21 and the inner diameter of the outer conductor 23 change at the deformed portion, and the characteristic impedance of the deformed portion changes. As a result, the deformed portion of the signal line 20 becomes a point of characteristic impedance mismatch, and the transmitted signal is reflected at this mismatch point, making it impossible to perform data communication between the electronic device 10 and the control device 30.

[0017] Thus, since an abnormality in the signal line 20 may prevent data communication between the electronic device 10 and the control device 30, it is important to detect whether an abnormality has occurred in the signal line 20. Furthermore, in some control systems, such as the control system 1 according to this embodiment, i.e., an advanced driver assistance system installed in a vehicle, there may be a distance between the electronic device 10 and the control device 30, or obstacles may prevent the signal line 20 from being routed in a straight line. In such cases, the length of the signal line 20 may be long, or the signal line 20 may be composed of multiple cables connected together.

[0018] In such cases, it is important not only to detect whether there is a problem with the signal line 20, but also to detect which part of the signal line 20 is experiencing the problem. This allows for quick identification and repair of the faulty part, and enables the replacement of only the faulty cable instead of replacing the entire signal line 20, thereby reducing repair time and the number of repair parts. Therefore, it is important not only to detect whether there is a problem with the signal line 20, but also to detect which part of the signal line 20 is experiencing the problem.

[0019] Therefore, in this embodiment, the control device 30 is configured to identify the abnormal portion of the signal line 20. The configuration of the control device 30 and the method for identifying the abnormal portion of the signal line 20 will be described in detail below.

[0020] The control device 30 is an ECU (Electronic Control Unit) including a communication unit 31, a storage unit 32, and a processing unit 33.

[0021] The communication unit 31 includes an interface circuit for connecting the control device 30 to an electronic device via the signal line 20. When the communication unit 31 receives data from the electronic device 10, it supplies the data to the processing unit 33. For example, in the present embodiment, the communication unit 31 deserializes the serialized data received from the in-vehicle camera as the electronic device 10 and supplies the original data to the processing unit 33. The communication unit 31 also outputs various signals output from the processing unit 33 to the electronic device 10. For example, in the present embodiment, as will be described later, the communication unit 31 outputs an abnormal part specifying signal for specifying an abnormal part of the signal line 20 to the electronic device 10.

[0022] The storage unit 32 has a storage medium such as an HDD (Hard Disk Drive), an SSD (Solid Disk Drive), or a semiconductor memory, and stores various computer programs, data, etc. used in the processing by the processing unit 33.

[0023] The processing unit 33 has one or more CPUs (Central Processing Unit) and its peripheral circuits, and executes various computer programs stored in the storage unit 32. The processing unit 33 is, for example, a processor. The processing unit 33 functions as an image generation unit 41, an abnormal part specifying signal transmission unit 42, a reflected signal detection unit 43, and an abnormal part specifying unit 44 by executing processing according to a computer program, and operates as a functional unit (module) that realizes a predetermined function. In the following description, when the processing is described with each functional unit 41 to 44 as the subject, it indicates that the processing unit 33 is executing a program that realizes each functional unit 41 to 44.

[0024] The image generation unit 41 generates an image based on the data received from the in-vehicle camera as the electronic device 10.

[0025] The abnormal location identification signal transmitting unit 42 transmits an abnormal location identification signal to the electronic device 10 via the signal line 20 from the communication unit 31 in response to the inability to receive data from or transmit data to the electronic device 10. The abnormal location identification signal is a signal for identifying an abnormal location in the signal line 20 (a point of characteristic impedance mismatch due to a break or bending), and is, for example, a rectangular pulse signal. In this embodiment, the abnormal location identification signal transmitting unit 42 transmits an abnormal location identification signal to the in-vehicle camera via the signal line 20 in response to the inability to receive data from the in-vehicle camera, which is an electronic device 10.

[0026] The reflected signal detection unit 43 detects the reflected signal of the abnormal location identification signal. When there is an abnormal location (a point of characteristic impedance mismatch due to a break or bending) in the signal line 20, as shown in Figure 3, when an abnormal location identification signal is transmitted at a certain time t1, the abnormal location identification signal is reflected at the abnormal location, and the reflected signal of the abnormal location identification signal is detected at a time t2, which is later than time t1. In this embodiment, as shown in Figure 3, in order to prevent false detection due to noise, etc., the reflected signal detection unit 43 detects a signal with a voltage value of Vth or higher within a predetermined time after transmitting the abnormal location identification signal as a reflected signal.

[0027] In response to detecting a reflected signal of the abnormal location identification signal, the abnormal location identification unit 44 calculates the reflection time T (the time from time t1 to time t2 in the example of Figure 3) from the time the abnormal location identification signal was transmitted until the reflected signal was detected, and identifies the abnormal location of the signal line 20 based on the reflection time T. Specifically, the fault location identification unit 44 identifies the abnormal location of the signal line 20 based on the reflection time T as follows.

[0028] Since the length L of the signal line and the transmission speed V (speed of light) of the abnormal location identification signal and the reflected signal are known in advance, if Tmax is the time required for the abnormal location identification signal to travel back and forth on the signal line 20, then Tmax can be expressed by the following equation (1). Also, if X is the length of the signal line from the control device 30 to the abnormal location on the signal line 20, then the reflection time T can be expressed by the following equation (2).

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[0029] Therefore, from equations (1) and (2) above, the wire length X from the control device 30 to the abnormal part of the signal line 20 can be expressed by the following equation (3).

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[0030] Therefore, for example, by pre-storing the second term on the right side of equation (3), i.e., the value of L / Tmax, in the storage unit 32, or by pre-storing the signal line length L and the time Tmax values ​​separately in the storage unit 32, the abnormal location identification unit 44 can substitute the calculated reflection time T into equation (3) to calculate the line length X from the control device 30 to the abnormal location on the signal line 20 based on the reflection time T, and identify the abnormal location.

[0031] Furthermore, for example, by creating an abnormal location identification table showing the relationship between reflection time T and line length X, as shown in Figure 4, based on equation (3), and storing it in the storage unit 32 in advance, the abnormal location identification unit 44 can refer to the abnormal location identification table and calculate the line length X from the control device 30 to the abnormal location on the signal line 20 based on the reflection time T, thereby identifying the abnormal location.

[0032] Furthermore, in this embodiment, if the signal line 20 is composed of multiple cables connected together, the length and connection order of each cable are stored in the storage unit 32 in advance. This allows the control device 30 to identify the cable experiencing the malfunction from among the multiple cables based on the cable length X from the control device 30 to the malfunctioning part of the signal line 20.

[0033] Figure 5 is a flowchart illustrating the contents of the abnormal part identification process according to this embodiment.

[0034] In step S1, the control device 30, in response to the inability to receive data from or transmit data to the electronic device 10, transmits an abnormal location identification signal to the electronic device 10 via the signal line 20 from the communication unit 31.

[0035] In step S2, the control device 30 determines whether it has detected a reflected signal of the abnormal location identification signal. As described above, the control device 30 determines that it has detected a reflected signal if it detects a signal whose voltage value is equal to or greater than a predetermined threshold Vth within a predetermined time after transmitting the abnormal location identification signal. The predetermined time can be, for example, the time Tmax required for the signal to travel back and forth on the signal line 20. If the control device 30 detects a reflected signal of the abnormal location identification signal within the predetermined time, it proceeds to the process in step S2. On the other hand, if the control device 30 does not detect a reflected signal of the abnormal location identification signal within the predetermined time, it terminates the current process.

[0036] In step S3, the control device 30 calculates the reflection time T from the time the abnormal area identification signal is transmitted until the reflected signal is detected.

[0037] In step S4, the control device 30 identifies the abnormal portion of the signal line 20 based on the reflection time T.

[0038] Furthermore, the method of notification when an abnormality occurs in the signal line 20 is not particularly limited. For example, the abnormality and location of the abnormality in the signal line 20 may be notified to a display device such as a display (not shown) at any time, such as when the abnormality is detected. Alternatively, when a fault diagnosis tool is connected to the control device 30, the abnormality and location of the abnormality in the signal line 20 may be notified on the fault diagnosis tool.

[0039] The control device 30 according to this embodiment, as described above, is connected to the electronic device 10 via a signal line 20, transmits an abnormal location identification signal to the electronic device 10 via the signal line 20, and in response to detecting a reflected signal of the abnormal location identification signal, calculates the reflection time T from the time the abnormal location identification signal is transmitted until the reflected signal is received, and identifies the abnormal location of the signal line 20 based on the reflection time T. Specifically, the control device 30 according to this embodiment is configured to identify the abnormal location of the signal line 20 by calculating the line length X from the control device 30 to the abnormal location of the signal line 20 based on the reflection time T.

[0040] As described above, this embodiment makes it possible to identify the location of the abnormal part of the signal line 20. Therefore, the abnormal part can be quickly identified and repaired. Furthermore, if the signal line 20 is composed of multiple cables, only the cable experiencing the abnormality can be replaced, rather than replacing the entire signal line 20. Thus, it is possible to shorten the repair time and reduce the number of repair parts when an abnormality occurs in the signal line 20.

[0041] Furthermore, in this embodiment, the signal line 20 is formed by connecting multiple cables, and the control device 30 is further configured to identify the cable in which the abnormality is occurring from among the multiple cables, based on the length X from the control device 30 to the abnormal part of the signal line 20 and the length of each of the multiple cables.

[0042] This allows for the rapid identification of faulty cables and their subsequent repair or replacement, further reducing repair time and the number of repair parts required.

[0043] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0044] For example, in the above embodiment, the computer program executed in the control device 30 may be provided in the form of a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium, or it may be provided as a computer program product. [Explanation of Symbols]

[0045] 1. Control System 10 Electronic equipment 20 signal lines 30 Control device

Claims

1. A control device connected to electronic equipment via signal lines, A signal for identifying the abnormal part is transmitted to the electronic device via the signal line. In response to detecting the reflected signal of the abnormal area identification signal, the reflection time from the transmission of the abnormal area identification signal to the reception of the reflected signal is calculated. Based on the reflection time, the system is configured to identify the abnormal portion of the signal line. Control device.

2. The system is configured to identify the abnormal part of the signal line by calculating the line length from the control device to the abnormal part of the signal line based on the reflection time. The control device according to claim 1.

3. The aforementioned signal line is formed by connecting multiple cables, The system is further configured to identify the cable experiencing the malfunction from among the multiple cables, based on the length of the cable from the control device to the faulty part of the signal line and the length of each of the multiple cables. The control device according to claim 1 or claim 2.

4. A method for identifying an abnormal part of a signal line by a control device connected to an electronic device via a signal line, A signal for identifying the abnormal part is transmitted to the electronic device via the signal line. In response to detecting the reflected signal of the abnormal area identification signal, the reflection time from the transmission of the abnormal area identification signal to the reception of the reflected signal is calculated. Based on the reflection time, the abnormal portion of the signal line is identified. How to identify abnormal areas.

5. A computer program for a control device connected to electronic equipment via signal lines, The control device, The electronic device is instructed to transmit a signal to identify the abnormal part via the signal line. In response to detecting the reflected signal of the abnormal area identification signal, the reflection time from the transmission of the abnormal area identification signal to the reception of the reflected signal is calculated. Based on the reflection time, the abnormal portion of the signal line is identified. A computer program designed to perform a task.

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