Electronic control device

Abstract

To provide an electronic control device capable of normally detecting an abnormality of a camera power supply.SOLUTION: A camera power supply 6 generates a power to be supplied to cameras 4 and 5. A discharge unit 19 can discharge the generated power of a camera power supply 6. A control unit 20 enables the operation of the camera power supply 6 and the operation of the discharge unit 19 to be enabled / disabled, respectively. An overcurrent detection unit 21 detects overcurrent of the camera power supply 6 in a state in which the discharge unit 19 is effectively operated by the control unit 20 at the time of activation of the camera power supply 6. An abnormality detection unit 20b of the control unit 20 detects an abnormality of the camera power supply 6 based on an overcurrent detection result of the overcurrent detection unit 21.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic control device that detects an abnormality in a camera power supply. [Background technology]

[0002] In recent years, when connecting a camera and an ECU via a communication line in a vehicle, the mainstream configuration is PoC (Power Over Coax), which superimposes power on the communication line. This PoC configuration makes it possible to supply power to the camera using the communication line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-2381 Summary of the Invention [Problem to be solved by the invention]

[0004] In the future, vehicles will be required to be equipped with many cameras that capture images of the surroundings and the interior of the vehicle. As the number of cameras increases, it is expected that the camera power supply unit will need to install a switch circuit to switch the power supply to each camera.

[0005] When a power supply abnormality occurs in multiple cameras, the power supply to the abnormal camera can be individually stopped by using a switch circuit, allowing the camera that is operating normally to continue taking pictures. However, depending on the number of connected cameras, it is necessary to add switch circuits and circuits to discharge the internal electric charge of the camera, which increases costs and size.

[0006] Furthermore, if the switch circuit is removed to solve the above problem, when multiple cameras are connected, it may be necessary to set the overcurrent detection threshold according to the total current when all cameras are operating. If one camera experiences a short circuit, depending on the characteristics of the components used, the overcurrent detection threshold may not be exceeded, making it impossible to detect a power supply abnormality. This example illustrates the problem of connecting multiple cameras, but even when a single camera is connected, depending on the characteristics of the components used, the overcurrent detection threshold may not function, making it impossible to detect a power supply abnormality.

[0007] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide an electronic control device that can normally detect abnormalities in a camera power supply that is provided to supply power to a camera. [Means for solving the problem]

[0008] The invention of claim 1 is directed to an electronic control device that uses a PoC configuration to supply power to a camera via a communication line. The camera power supply generates power to be supplied to the camera. The discharge unit enables the generated power for the camera power supply to be discharged. The enable control unit enables the operation of the camera power supply and the discharge unit to be switched between enabled and disabled. The overcurrent detection unit detects an overcurrent in the camera power supply when the camera power supply is started up, with the enable control unit enabling the discharge unit to operate. The abnormality detection unit detects an abnormality in the camera power supply based on the overcurrent detection result of the overcurrent detection unit, so that an abnormality in the camera power supply can be detected correctly.

[0009] The invention of claim 5 is directed to an electronic control device that uses a PoC configuration to supply power to a camera via a communication line. The camera power supply generates power to be supplied to the camera. The overcurrent detection unit detects overcurrent in the camera power supply when the camera power supply is started up. The threshold change unit changes the overcurrent detection threshold used by the overcurrent detection unit to detect overcurrent. The abnormality detection unit detects an abnormality in the camera power supply based on the overcurrent detection result of the overcurrent detection unit obtained by changing the overcurrent detection threshold using the threshold change unit, so that abnormalities in the camera power supply can be detected correctly. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram illustrating a system configuration according to a first embodiment. [Figure 2] Electrical configuration diagram of the discharge unit in the first embodiment [Figure 3] Time chart in the first embodiment [Figure 4] Explanatory diagram of a comparative example [Figure 5] 10 is a flowchart illustrating an outline of an abnormality detection process according to the second embodiment. [Figure 6] FIG. 10 is a block diagram illustrating a system configuration according to a third embodiment. [Figure 7] Time chart in the third embodiment [Figure 8] 10 is a flowchart illustrating an outline of an abnormality detection process according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the electronic control device will be described. Components that perform the same functions in the respective embodiments will be assigned the same reference numerals, and descriptions thereof may be omitted.

[0012] (First embodiment) The first embodiment will be described with reference to Fig. 1 to Fig. 4. As shown in Fig. 1, the electronic control device 1 includes a control unit 20 connected to a memory 23, and also includes a camera power supply 6, PoC filters 7 and 9, deserializers 17 and 18, and a discharge unit 19. The electronic control device 1 is connected to a camera 4 via a coax cable 2. The electronic control device 1 is also connected to a camera 5 via a coax cable 3. The coax cables 2 and 3 are used as communication lines between the electronic control device 1 and the cameras 4 and 5, and are also used as power supply lines for supplying power from the camera power supply 6 to the cameras 4 and 5.

[0013] The control unit 20 is configured to include a microcomputer and performs various controls by executing programs stored in the memory 23. The control unit 20 in this embodiment has functions as an enable control unit 20a, an abnormality detection unit 20b, and a communication unit 20z. The communication unit 20z has the function of executing communication processing between the cameras 4 and 5 and the communication unit 22 of the camera power supply 6 using a predetermined communication standard. The camera power supply 6 is a power supply circuit for generating power to be supplied to the cameras 4 and 5. The camera power supply 6 has the communication unit 22 and is capable of communicating with the control unit 20. The camera power supply 6 can switch between enabling and disabling the power supply to the cameras 4 and 5 based on enable control by the control unit 20.

[0014] PoC filters 7 and 9 are provided on the power supply lines between the camera power supply 6 and the coax cables 2 and 3 to remove noise components from the power supply. The PoC filters 7 and 9 are low-pass filters configured with resistors and inductors (not shown) in the illustrated configuration. The PoC filters are not limited to the above configuration.

[0015] Cameras 4 and 5 are also provided with PoC filters 8 and 10, respectively. In addition to the PoC filter 8, camera 4 is provided with a serializer 15, a coupling capacitor 12, and a video signal processing unit (not shown). In addition to the PoC filter 10, camera 5 is provided with a serializer 16, a coupling capacitor 14, and a video signal processing unit (not shown).

[0016] The PoC filters 8 and 10 of the cameras 4 and 5 are also configured as low-pass filters with resistors and inductors (unnumbered) configured in the manner shown. The PoC filters shown here are not limited to the above configuration. The PoC filters 8 and 10 remove noise components from the power supplied through the coax cables 2 and 3, respectively, and supply power to the cameras 4 and 5.

[0017] The cameras 4 and 5 are vehicle cameras that capture images of the surroundings and interior of the vehicle, respectively, and convert them into video signals. When the camera 4 transmits a video signal to the control unit 20, the control unit 20 first 2 C performs initial settings between the serializer 15 and the deserializer 17 and establishes a link. Then, the camera 4 transmits a video signal to the serializer 15. The serializer 15 outputs the video signal to the deserializer 17 via the coupling capacitor 12, the coax cable 2, and the coupling capacitor 11. The deserializer 17 transmits the video signal to the control unit 20 by communication compliant with the MIPI standard.

[0018] When transmitting a video signal from the camera 5 to the control unit 20, the control unit 20 first 2 C performs initial settings between the serializer 16 and the deserializer 18 and establishes a link. Subsequently, the camera 5 transmits a video signal to the serializer 16. The serializer 16 outputs the video signal to the deserializer 18 via the coupling capacitor 14, the coax cable 3, and the coupling capacitor 13. The deserializer 18 transmits the video signal to the control unit 20 by communication compliant with the MIPI standard. As a result, the control unit 20 receives the video signals from the cameras 4 and 5 and records them sequentially in the memory 23. Here, I 2 Although an example of a method for transmitting a video signal using the C and MIPI communication standards has been described, the present invention is not limited to this, and the video signal may be transmitted using other communication standards.

[0019] The electronic control device 1 is provided with a discharge unit 19 as a peripheral circuit of the camera power supply 6. The discharge unit 19 is connected to the output node of the camera power supply 6 and to a node on the upstream side of the PoC filters 7 and 9. The discharge unit 19 is a circuit block that enables the power generated by the camera power supply 6 to be discharged, and its operation can be switched between enabled and disabled under the control of an enable control unit 20a of the control unit 20.

[0020] As shown in FIG. 2, the discharge unit 19 includes a resistor 24 through which the discharge current Id is passed from the camera power supply 6, and a switch unit 25 that enables / disables the operation of the discharge unit 19. The switch unit 25 is configured with an N-channel MOS transistor and is configured with an additional Zener diode 25a for gate protection of the MOS transistor. The control unit 20 controls the gate voltage of the MOS transistor to turn the switch unit 25 on and off. When the control unit 20 turns on the switch unit 25, the discharge current Id passes through the resistor 24 to ground, allowing the discharge current Id to flow. The resistance value of the resistor 24 is set so that it is not detected as an overcurrent during normal operation of the cameras 4 and 5, but is detected only when there is an abnormality in the power supply on the cameras 4 and 5 side.

[0021] The overcurrent detection operation using the above configuration will be described. 3, the control unit 20 raises the enable control signal for the camera power supply 6. This starts up the camera power supply 6. When the camera power supply 6 starts up, an operating current for the camera power supply 6 flows.

[0022] Consider the case where the camera power supply 6 has an internal short circuit. When there is an abnormality in the camera power supply 6, the operating current becomes larger than when there is no abnormality (see T2 to T4 in FIG. 3). When there is an abnormality, the control unit 20 activates the enable control signal for the discharge unit 19 at timing T2, enabling the discharge unit 19 to operate, thereby adding the discharge current Id to the operating current. The overcurrent detection unit 21 detects the output current of the camera power supply 6 to determine whether it has reached the overcurrent detection threshold It.

[0023] If there is an abnormality in the camera power supply 6, the output current of the camera power supply 6 exceeds the overcurrent detection threshold It. Therefore, the overcurrent detection unit 21 detects an overcurrent abnormality at timing T3. The overcurrent detection unit 21 detects whether or not there is an overcurrent abnormality, and if there is an abnormality, it sets a flag (see T3). The camera power supply 6 is equipped with an internal register, and if there is an abnormality in the camera power supply 6, it records it as an abnormality flag in the internal register. After the overcurrent detection unit 21 detects whether or not there is an overcurrent abnormality, when that information is input to the control unit 20, the control unit 20 stops the enable control at timing T4 and stops the discharge current Id. If the abnormality continues after that, the control unit 20 outputs an enable control signal to stop the camera power supply 6 at timing T5. The camera power supply 6 then stops output. Since power is no longer supplied from the camera power supply 6 to the cameras 4 and 5, the cameras 4 and 5 will also not start up.

[0024] On the other hand, under normal circumstances, even if the control unit 20 activates the camera power supply 6 at timing T1 and then activates the discharge unit 19 to discharge, the output current of the camera power supply 6 will not exceed the overcurrent detection threshold It (see the dashed current portion). In this case, the control unit 20 disables the operation of the discharge unit 19 after the overcurrent detection process by the overcurrent detection unit 21 is completed (timing T4), thereby setting the discharge current Id to zero. Then, the camera power supply 6 continues to supply power to the cameras 4 and 5 through the PoC filters 7 and 9 and the coax cables 2 and 3 (see the dashed current portion after timing T5).

[0025] If no abnormality is detected, the control unit 20 issues a start-up instruction to the cameras 4 and 5. When the start-up instruction is input, the cameras 4 and 5 are initialized, and at timing T6, the cameras 4 and 5 start normal operation. This makes it possible to determine whether or not there is an abnormality in the camera power supply 6.

[0026] <Explanation of Comparative Example> A comparative example is shown in Figure 4. In Figure 4, switch circuits SW1 and SW2 are provided in the power supply path from the camera power supply 6 to each of the cameras 4 and 5. Switch circuits SW1 and SW2 are provided for each of the cameras 4 and 5, and if a power abnormality occurs in the camera power supply 6, the power supply to each of the cameras 4 and 5 can be stopped individually by individually turning off the switch circuits SW1 and SW2. This makes it possible to continue imaging operations for cameras 4 and 5 that are operating normally. However, as the number of connected cameras 4 and 5 increases, the number of switch circuits SW1 and SW2 also increases, and it becomes necessary to provide a discharge unit 19 for each of the cameras 4 and 5 to discharge the internal charge, which undesirably results in increased costs and size.

[0027] <Summary of this embodiment> According to this embodiment, when the camera power supply 6 is started up, the overcurrent detection unit 21 detects whether or not there is an overcurrent in the camera power supply 6 with the discharge unit 19 being effectively operated by the control unit 20, and detects an abnormality in the camera power supply 6 based on the overcurrent detection result of the overcurrent detection unit 21. This allows for normal detection of a power supply abnormality without using the switch circuits SW1 and SW2. Whether or not there is a power supply abnormality is determined based on the output current of the camera power supply 6, so it is possible to identify whether or not there is a power supply abnormality.

[0028] The control unit 20 enables the discharge unit 19 to operate after starting the camera power supply 6, disables the operation of the discharge unit 19 after the overcurrent detection process by the overcurrent detection unit 21 is completed, and instructs the cameras 4 and 5 to start if no abnormality is detected. Since an abnormality can be detected immediately after starting the camera power supply 6, the output of the camera power supply 6 can be stopped immediately. As a result, the power supply abnormality is not allowed to continue, and the components can be protected.

[0029] The resistance value of resistor 24 is set so that it is not detected as an overcurrent during normal operation of cameras 4 and 5, but is detected only when there is an abnormality in camera power supply 6, so that the overcurrent detection threshold It can be set to an appropriate level. This allows overcurrent to be detected only when there is a power supply abnormality, and prevents erroneous detection of a power supply abnormality during normal operation.

[0030] (Second embodiment) The second embodiment will be described with reference to FIG. 5. In this embodiment, a processing example using the configuration of the first embodiment will be described in detail. The operation after the ignition switch in the vehicle is turned on by the occupant will be described. When the ignition switch is turned on by the occupant to start the engine, the main power supply of the electronic control unit 1 is turned on in S10 of FIG. 5. Then, power supply to each circuit of the electronic control unit 1 begins, and the control unit 20 is started in S20.

[0031] In S30, the control unit 20 activates the camera power supply 6 through enable control (timing T1 in FIG. 3). In S40, the control unit 20 activates the discharge unit 19 through enable control (timing T2 in FIG. 3). In S50, the overcurrent detection unit 21 determines whether or not there is an abnormality in the camera power supply 6 by detecting whether or not the output current of the camera power supply 6 exceeds the overcurrent detection threshold It. The camera power supply 6 has an internal register, and if there is an abnormality in the camera power supply 6, it is recorded as an abnormality flag in the internal register (timing T3 in FIG. 3).

[0032] If an abnormality has occurred in the camera power supply 6, the control unit 20 determines that the abnormality in the camera power supply 6 has been confirmed, and disables the operation of the discharge unit 19 and stops the discharge unit 19 in S60 (timing T4 in FIG. 3). The control unit 20 stops the camera power supply 6 by enable control in S70 (timing T5 in FIG. 3). The control unit 20 saves a power supply abnormality log in the memory 23 in S80.

[0033] If an abnormality occurs in the camera power supply 6, the electronic control unit 1 operates in a function-restricted state in S90, and only the minimum communication processing such as CAN can be performed. After that, if the main power is on in S100, the electronic control unit 1 continues to operate in a function-restricted state, and stops all operations when the ignition switch is operated to turn off the main power.

[0034] On the other hand, if the control unit 20 determines that there is no abnormality in the camera power supply 6, it determines NO in S50 and performs an initial startup determination in S110. If it is an initial startup, the control unit 20 proceeds to S120, where it disables the operation of the discharge unit 19 and stops the discharge unit 19 (timing T4 in FIG. 3). The control unit 20 performs initialization settings on the cameras 4 and 5 in S130, and when the cameras 4 and 5 start operating, an operating current begins to flow through the cameras 4 and 5 (timing T6 in FIG. 3).

[0035] When the operation of the cameras 4 and 5 starts in S130, the control unit 20 detects the I 2 Detects communication errors related to cameras 4 and 5, such as C, MIPI, and LVDS. For example, 2 In C communication, communication abnormalities such as NACK detection, timeout, and verification abnormality are detected. When executing communication processing, the communication unit 20z adds an error detection code to the communication and prohibits the write operation of the communication data after the communication is completed. This enables functional safety.

[0036] If a communication abnormality with the cameras 4 and 5 is detected, the control unit 20 turns off the camera power supply 6 in S150, returns the process to S30, and restarts the camera power supply 6 by turning it on again. Subsequently, from S50 onwards, the overcurrent detection unit 21 again detects whether an overcurrent is occurring in the output current of the camera power supply 6, thereby detecting whether there is an abnormality in the camera power supply 6. Through this series of processes, it is determined whether the abnormality is in the communication with the cameras 4 and 5 or in the camera power supply 6 itself.

[0037] If there is a power supply abnormality in the camera power supply 6, the control unit 20 judges YES in S50 and proceeds to the processing of S60 to S100. Conversely, if there is no power supply abnormality in the camera power supply 6, the control unit 20 judges NO in S50 and therefore performs the initial startup judgment again in S110. Since this is the second startup and not the initial startup, it determines in S160 that there is a communication abnormality. The control unit 20 saves a communication abnormality log in the memory 23 in S160. The control unit 20 stops only the camera (for example, 4 here) that was determined to be abnormal in S170 and returns to the processing flow from S120 onwards. At this time, it can be determined that there is a communication abnormality with camera 4 and not an abnormality in the camera power supply 6. The control unit 20 starts communication with another camera 5 in S130, and if no communication abnormality is detected, it judges NO in S140 and executes normal operation in S180.

[0038] If a communication abnormality with another camera 5 is detected in S140 during the second startup, the control unit 20 stops the operation of the camera power supply 6 again in S150, returns the process to S30, and repeats the process. If there is a communication abnormality with another camera 5 at this time, the control unit 20 saves a communication abnormality log in the memory 23 in S160, and also stops the other camera 5 in S170. This makes it possible to determine whether the abnormality is occurring in the camera power supply 6 or in one of the cameras (e.g., 4, 5).

[0039] On the other hand, if no camera communication abnormality is detected in S140 during the first or second or subsequent startup, communication with cameras 4 and 5 is determined to be normal, and normal operation begins in S180. Until the main power is turned off in S190, control unit 20 constantly detects communication abnormalities with cameras 4 and 5. If the main power is turned off in S190, control unit 20 stops all operations.

[0040] <Summary of this embodiment> This embodiment provides the same operational effects as the first embodiment. Furthermore, if the control unit 20 determines that a communication abnormality has occurred after the cameras 4 and 5 have started operating, it restarts the camera power supply 6 and causes the overcurrent detection unit 21 to again detect whether an overcurrent has been detected. This configuration makes it possible to distinguish between a power supply abnormality in the camera power supply 6 and a communication abnormality. Since the camera power supply 6 can be shut off without allowing the abnormality in the camera power supply 6 to continue, components provided downstream of the camera power supply 6 (for example, PoC filters 7-10) can be protected.

[0041] (Third embodiment) A third embodiment will be described with reference to Figs. 6 and 7. In the third embodiment, an embodiment in which overcurrent detection thresholds It1 and It2 for detecting overcurrent are changed will be described. In this embodiment, as shown in Fig. 6, the control unit 20 has a function as a threshold change unit 20c. The other configurations are the same as those of the first and second embodiments, and therefore description thereof will be omitted.

[0042] 7, the control unit 20 first discharges the load capacitance using the discharge unit 19 before timing T31, and then stops the operation of the discharge unit 19 using enable control. The control unit 20 also sets the overcurrent detection threshold It1 of the overcurrent detection unit 21 as an initial value. The overcurrent detection threshold It1 is set in advance to a value that is smaller than an overcurrent detection threshold It2, which will be described later, and is larger than the current consumption when power is supplied to the cameras 4 and 5. The overcurrent detection threshold It1 is equivalent to a predetermined pre-change threshold.

[0043] The overcurrent detection threshold It1 is set so that when the cameras 4 and 5 are operating normally, even if power is supplied from the camera power supply 6, the overcurrent detection unit 21 will not detect an overcurrent, but will detect an overcurrent only when there is an abnormality in the cameras 4 and 5. In addition, the overcurrent detection thresholds It1 and It2 are set to be equal to or lower than the ratings of the components of the PoC filters 7 and 9.

[0044] At timing T31, the control unit 20 activates the enable control signal for the camera power supply 6, activating the camera power supply 6. If, at this time, camera 4 or 5 experiences an internal abnormality (e.g., a short circuit in camera 4) causing an abnormality in the camera power supply 6, the operating current will be larger than when there is no abnormality. If an abnormality occurs in the camera power supply 6, the operating current will exceed the preset overcurrent detection threshold It1. Therefore, the overcurrent detection unit 21 detects an overcurrent at timing T32 and sets an abnormality detection flag (see the solid line portion of the current). If the overcurrent detection unit 21 determines that an abnormality exists as a result of detecting the presence or absence of an abnormality, the control unit 20 shuts down the camera power supply 6 at timing T33. The control unit 20 then operates the discharge unit 19 by enabling control, shorting the output of the camera power supply 6 to ground.

[0045] Conversely, in a normal state, the output current of camera power supply 6 does not exceed the preset overcurrent detection threshold It1, and overcurrent detection unit 21 does not detect an abnormality (see the dashed current portion). In this case, control unit 20 initializes cameras 4 and 5 to operate, but at timing T34, before cameras 4 and 5 start operating, it changes the setting of overcurrent detection threshold It1 of overcurrent detection unit 21 to overcurrent detection threshold It2 (>It1).

[0046] The overcurrent detection threshold It2 is set to a threshold value greater than the output current of the camera power supply 6 while all of the cameras 4 and 5 are operating. Thereafter, at timing T35, the cameras 4 and 5 start normal operation, and a normal operating current flows through the cameras 4 and 5. Even if the operating current of the cameras 4 and 5 increases and the output current of the camera power supply 6 also increases, the overcurrent detection threshold It2 is not reached and the overcurrent detection unit 21 does not detect an overcurrent (see the normal operation after timing T35 indicated by the dashed line in FIG. 7).

[0047] <Summary of this embodiment> According to this embodiment, the control unit 20 changes the overcurrent detection thresholds It1 and It2 used by the overcurrent detection unit 21 to detect an overcurrent, and detects whether or not there is an abnormality in the camera power supply 6 based on the overcurrent detection result of the overcurrent detection unit 21 obtained by changing the overcurrent detection thresholds It1 and It2 using the threshold change unit 20c. As a result, it is possible to normally detect a power supply abnormality without using the switch circuits SW1 and SW2. Whether or not there is a power supply abnormality is determined based on the output current of the camera power supply 6, so it is possible to determine whether or not there is a power supply abnormality.

[0048] The control unit 20 changes the overcurrent detection threshold It2 to be larger than the overcurrent detection threshold It1 before the change depending on the operating state of the cameras 4 and 5, and detects an abnormality in the camera power supply 6 based on the overcurrent detection result of the overcurrent detection unit 21. Because the overcurrent detection thresholds It1 and It2 can be changed depending on the operating state of the cameras 4 and 5, they can be set so that an overcurrent is not detected during normal operation after the cameras 4 and 5 start operating.

[0049] The overcurrent detection threshold It1 is set so that when the cameras 4 and 5 are normal, even if power is supplied from the camera power supply 6, the overcurrent detection unit 21 will not detect it as an overcurrent, but will detect it as an overcurrent only when there is an abnormality in the cameras 4 and 5. This prevents erroneous detection of a power supply abnormality when the cameras 4 and 5 are normal. The overcurrent detection thresholds It1 and It2 are set to be equal to or lower than the ratings of the components of the PoC filters 7 and 9 on the power line, preventing failure of the components of the PoC filters 7 and 9.

[0050] (Fourth embodiment) The fourth embodiment will be described with reference to FIG. 8. In this embodiment, a processing example using the configuration of the third embodiment will be described in detail. The operation after the ignition switch in the vehicle is turned on by the occupant will be described. When the ignition switch is turned on by the occupant to start the engine, the main power supply of the electronic control unit 1 is turned on in S310 of FIG. 8. Then, power supply to each circuit of the electronic control unit 1 begins, and the control unit 20 is started in S320. In S325, the control unit 20 enables the overcurrent detection unit 21 and sets the threshold of the overcurrent detection unit 21 to the overcurrent detection threshold It1 (threshold before change).

[0051] The control unit 20 activates the discharge unit 19 by enable control in S330 to perform discharge, and then activates the discharge unit 19 by enable control in S340 to stop the operation of the discharge unit 19. The control unit 20 activates the camera power supply 6 by enable control in S350 (timing T31 in FIG. 7).

[0052] It is preferable that the camera power supply 6 is configured so that the magnitude of its output voltage can be adjusted by the control unit 20. When the camera power supply 6 is first started up, a first predetermined voltage that is large enough not to reach the maximum rated power supply voltage of the cameras 4 and 5 may be output as a default value. This increases the abnormal current when the camera is abnormal, and increases the current difference between normal and abnormal conditions, thereby improving the accuracy of overcurrent detection.

[0053] Then, in S360, the overcurrent detection unit 21 detects whether the current flowing to the camera power supply 6 exceeds the overcurrent detection threshold It1, and determines whether there is an abnormality in the camera power supply 6. The camera power supply 6 has an internal register, and if there is an abnormality in the camera power supply 6, it is recorded in the internal register as an abnormality flag.

[0054] If an abnormality is found in the camera power supply 6, the control unit 20 determines that the abnormality in the camera power supply 6 has been confirmed, and in S370 the control unit 20 stops the camera power supply 6 by enabling control (timing T33 in FIG. 7). In S380 the control unit 20 starts the discharge unit 19 to discharge the power. In S390, the power supply abnormality log is saved in the memory 23. In S400, the electronic control unit 1 operates in a functionally restricted state, allowing only minimum communication processing such as CAN to be performed. Thereafter, if the main power supply is on in S410, the electronic control unit 1 continues to operate in a functionally restricted state, and all operations are stopped when the ignition switch is operated to turn off the main power supply.

[0055] On the other hand, if the control unit 20 determines that there is no abnormality in the camera power supply 6, it determines NO in S360 and performs an initial startup determination in S420. If it is an initial startup, the control unit 20 proceeds to S430 and changes the detection threshold of the overcurrent detection unit 21 to the overcurrent detection threshold It2 (changed threshold) (timing T34 in FIG. 7). In S440, the control unit 20 performs initialization settings to start the operation of the cameras 4 and 5. When the cameras 4 and 5 start operating, an operating current begins to flow through the cameras 4 and 5 (timing T35 in FIG. 7).

[0056] In this case, the control unit 20 may reduce the output voltage of the camera power supply 6 from the initial startup to stabilize the operating voltage. In the above-mentioned S350, a first predetermined voltage large enough not to reach the maximum rated power supply voltage of the cameras 4 and 5 is applied in advance as a default value to inspect the output current of the camera power supply 6. However, when operating the cameras 4 and 5 normally, a second predetermined voltage smaller than the first predetermined voltage may be set as the output voltage of the camera power supply 6. This allows the operating current during normal operation to be relatively small. Because overcurrents become excessively large during inspection at startup, the difference between abnormal and normal conditions can be increased, allowing for stable detection of overcurrents during startup.

[0057] When the cameras 4 and 5 start operating in S440, the control unit 20 detects the I 2 Detects communication errors related to cameras 4 and 5, such as C, MIPI, and LVDS. For example,2 In C communication, communication abnormalities such as NACK detection, timeout, and verification abnormality are detected. When executing communication processing, the communication unit 20z adds an error detection code to the communication and prohibits the write operation of the communication data after the communication is completed. This enables functional safety.

[0058] If a communication abnormality between the cameras 4 and 5 is detected, the control unit 20 turns off the camera power supply 6 in S460, returns to S325, and resets the detection threshold of the overcurrent detection unit 21 to the overcurrent detection threshold It1. Then, the control unit 20 starts the discharge unit 19 to discharge in S330, and then stops the operation of the discharge unit 19 in S340. The control unit 20 restarts the camera power supply 6 by turning it on again in S350. Next, in S360, the overcurrent detection unit 21 again detects whether an overcurrent is occurring in the output current of the camera power supply 6, thereby detecting the presence or absence of an abnormality in the camera power supply 6. This distinguishes between an abnormality in communication with the cameras 4 and 5 and an abnormality in the camera power supply 6.

[0059] If there is a power supply abnormality in the camera power supply 6, the control unit 20 determines YES in S360 and proceeds to the processing of S370 to S410. Conversely, if there is no power supply abnormality in the camera power supply 6, the control unit 20 determines NO in S360 and therefore performs an initial startup determination again in S420. Since this is the second startup and not the initial startup, the control unit 20 proceeds to S470 and determines that there is a communication abnormality. In S470, the control unit 20 saves a communication abnormality log in the memory 23. The control unit 20 stops only the camera (for example, 4 here) determined to be abnormal in S480 and returns to the processing flow from S430 onwards. At this time, it can be determined that there is a communication abnormality with camera 4 and not an abnormality in the camera power supply 6. The control unit 20 starts communication with another camera 5 in S440, and if no communication abnormality is detected, the control unit 20 determines NO in S450 and executes normal operation in S490.

[0060] If a communication abnormality with another camera 5 is also detected in S450 during the second startup, the control unit 20 stops the operation of the camera power supply 6 again in S460 and repeats the process from S325. If there is a communication abnormality with another camera 5 at this time, the control unit 20 saves a communication abnormality log in the memory 23 in S470 and also stops the other camera 5 in S480. This makes it possible to determine whether the abnormality is occurring in the camera power supply 6 or in one of the cameras (e.g., 4, 5).

[0061] On the other hand, if no camera communication abnormality is detected in S450 at the first or second or subsequent startup, communication with cameras 4 and 5 is determined to be normal, and normal operation begins in S490. Until the main power is turned off in S500, control unit 20 constantly detects communication abnormalities with cameras 4 and 5. If the main power is turned off in S500, control unit 20 stops all operations.

[0062] <Summary of this embodiment> This embodiment provides the same advantageous effects as those of the third embodiment. Furthermore, since the control unit 20 changes the overcurrent detection threshold It1 from the previous threshold It1 to the overcurrent detection threshold It2 in step S430 before the cameras 4 and 5 start operating, it is possible to detect whether an overcurrent has occurred using the correct overcurrent detection threshold It2 when the cameras 4 and 5 are operating.

[0063] Furthermore, if a communication abnormality is determined in S440 after cameras 4 and 5 have started operating, camera power supply 6 is restarted via S460, S325, S330, and S340, and overcurrent detection unit 21 again detects overcurrent in S360. If overcurrent detection unit 21 detects an overcurrent, it determines that there is a power abnormality in camera power supply 6, and if no overcurrent is detected, it can be concluded that there is a communication abnormality. This makes it possible to distinguish between a power abnormality and a communication abnormality, and protect components without allowing the power abnormality to continue.

[0064] When the camera power supply 6 is restarted (S460 → S350), the overcurrent detection unit 21 changes the detection threshold from the overcurrent detection threshold It2 (threshold after change) back to the overcurrent detection threshold It1 (threshold before change) to detect an overcurrent. This makes it possible to detect a power supply abnormality immediately after the camera power supply 6 is restarted.

[0065] (Other embodiments) The present invention is not limited to the above-described embodiment, and the following modifications or extensions are possible. The communication lines are not limited to the coax cables 2 and 3. Although the system in which the electronic control device 1 is connected to a plurality of cameras 4 and 5 has been exemplified, the present invention is not limited to this and may be applied to a system in which one camera (for example, 4) is connected, or to a system in which three or more cameras 4 and 5 and other cameras are connected.

[0066] The present disclosure includes the following disclosure in addition to the disclosure described in the claims. [1] An electronic control device (1) that uses a PoC configuration to supply power to a camera through a communication line, a camera power supply (6) that generates power to be supplied to the camera; a discharge unit (19) that enables the generated power supply of the camera power supply to be discharged; an enable control unit (20a) that enables / disables the operations of the camera power supply and the discharge unit; an overcurrent detection unit (21) that detects an overcurrent in the camera power supply while the discharge unit is being enabled by the enable control unit when the camera power supply is started up; an abnormality detection unit (20b) that detects an abnormality in the camera power supply based on the overcurrent detection result of the overcurrent detection unit.

[0067] [2] The enable control unit enables the discharge unit to operate after the camera power supply is started, disables the operation of the discharge unit after the overcurrent detection unit completes the overcurrent detection process, and instructs the camera to start up if the abnormality detection unit does not detect the abnormality [1].

[0068] [3] The discharge unit includes a resistor (24) that conducts current from the camera power supply, The resistance value of the resistor is set so that the overcurrent is not detected by the overcurrent detection unit during normal operation of the camera, but is detected only when there is an abnormality in the camera power supply. [1] or [2]

[0069] [4] If a communication abnormality is determined after the camera starts operating, the camera power supply is restarted and the overcurrent detection unit detects the presence or absence of the overcurrent again.

[0070] [5] An electronic control device (1) that uses a PoC configuration to supply power to a camera through a communication line, a camera power supply (6) that generates power to be supplied to the camera; an overcurrent detection unit (21) that detects an overcurrent in the camera power supply when the camera power supply is started up; a threshold value changing unit (20c) that changes an overcurrent detection threshold value used by the overcurrent detection unit to detect the overcurrent; an abnormality detection unit (20b) that detects an abnormality in the camera power supply based on an overcurrent detection result of the overcurrent detection unit obtained by changing the overcurrent detection threshold value using the threshold change unit.

[0071] [6] the threshold change unit changes the overcurrent detection threshold so as to increase the overcurrent detection threshold from a predetermined pre-change threshold in accordance with an operating state of the camera; The electronic control device according to [5], wherein the abnormality detection unit detects an abnormality in the camera power supply based on the overcurrent detection result of the overcurrent detection unit.

[0072] [7] a component is provided on a power supply line between the camera power supply and the camera; The pre-change threshold is set so that even if current is supplied from the camera power supply during normal operation of the camera, it will not be detected as an overcurrent by the overcurrent detection unit, but will be detected as an overcurrent only when there is an abnormality in the camera, and is set to be equal to or less than the rated value of the components on the power supply line [5] or [6].

[0073] [8] The electronic control device according to any one of [5] to [7], wherein the threshold change unit changes the overcurrent detection threshold before the camera starts operating.

[0074] [9] An electronic control device according to any one of [5] to [8], wherein if a communication abnormality is determined after the camera starts operating, the camera power supply is restarted and the overcurrent detection unit detects an overcurrent again.

[0075]

[10] When the camera power supply is restarted, the overcurrent detection unit returns the overcurrent detection threshold from the changed threshold to the pre-change threshold and detects an overcurrent [9].

[0076]

[11] The electronic control device according to any one of [1] to

[10] , further comprising a communication unit (20z) that performs communication via the communication line with an error detection code and prohibits a write operation of the communication data after the communication is completed.

[0077]

[12] The camera power supply is configured to be able to change the output voltage, and when starting up the camera and detecting an abnormality in the camera power supply, the output voltage is set to a first predetermined voltage that does not reach the maximum rated power supply voltage of the camera, and before operating the camera normally, the output voltage is changed to a second predetermined voltage that is lower than the first predetermined voltage.

[0078] The techniques described in this disclosure may be implemented by a special purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the techniques described in this disclosure may be implemented by a special purpose computer configured with a processor comprising one or more dedicated hardware logic circuits. Alternatively, the techniques described in this disclosure may be implemented by one or more special purpose computers configured with a processor comprising one or more hardware logic circuits in combination with a processor and memory programmed to perform one or more functions. Furthermore, a computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0079] Although the present disclosure has been described based on the above-described embodiment, it is understood that the present disclosure is not limited to the embodiment or the structure described in the embodiment. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0080] In the drawing, 1 indicates an electronic control device, 2 and 3 indicate coax cables (communication lines), 4 and 5 indicate cameras, 6 indicates a camera power supply, 19 indicates a discharge unit, 20 indicates a control unit, 20a indicates an enable control unit, 21 indicates an overcurrent detection unit, 20b indicates an abnormality detection unit, and 20z indicates a communication unit.

Claims

1. An electronic control device (1) that supplies power to a camera through a communication line using a PoC configuration, a camera power supply (6) that generates power to be supplied to the camera; a discharge unit (19) that enables the generated power supply of the camera power supply to be discharged; an enable control unit (20a) that enables / disables the operations of the camera power supply and the discharge unit; an overcurrent detection unit (21) that detects an overcurrent in the camera power supply while the discharge unit is being effectively operated by the enable control unit when the camera power supply is started up; an abnormality detection unit (20b) that detects an abnormality in the camera power supply based on an overcurrent detection result of the overcurrent detection unit.

2. 2. The electronic control device according to claim 1, wherein the enable control unit enables the discharge unit to operate after the camera power supply is started, disables the operation of the discharge unit after the overcurrent detection unit completes the overcurrent detection process, and instructs the camera to start up if the abnormality detection unit does not detect the abnormality.

3. The discharge unit includes a resistor (24) that conducts current from the camera power supply, 2. The electronic control device according to claim 1, wherein the resistance value of the resistor is set so that the overcurrent is not detected by the overcurrent detection unit during normal operation of the camera, but is detected only when an abnormality occurs in the camera power supply.

4. 2. The electronic control device according to claim 1, wherein if a communication abnormality is determined after the camera has started operating, the camera power supply is restarted and the overcurrent detection unit detects again whether or not an overcurrent exists.

5. An electronic control device (1) that supplies power to a camera through a communication line using a PoC configuration, a camera power supply (6) that generates power to be supplied to the camera; an overcurrent detection unit (21) that detects an overcurrent in the camera power supply when the camera power supply is started; a threshold value changing unit (20c) that changes an overcurrent detection threshold value used by the overcurrent detection unit to detect the overcurrent; an abnormality detection unit (20b) that detects an abnormality in the camera power supply based on an overcurrent detection result of the overcurrent detection unit obtained by changing the overcurrent detection threshold value using the threshold change unit.

6. the threshold change unit changes the overcurrent detection threshold so as to increase the overcurrent detection threshold from a predetermined pre-change threshold in accordance with an operating state of the camera; 6. The electronic control device according to claim 5, wherein the abnormality detection section detects an abnormality in the camera power supply based on an overcurrent detection result from the overcurrent detection section.

7. a component is provided on a power supply line between the camera power supply and the camera; 7. The electronic control device according to claim 6, wherein the pre-change threshold is set so that even if current is supplied from the camera power supply during normal operation of the camera, the pre-change threshold is not detected as an overcurrent by the overcurrent detection unit, but is detected as an overcurrent only when there is an abnormality in the camera, and is set to be less than the rated value of components on the power supply line.

8. The electronic control device according to claim 5 , wherein the threshold change unit changes the overcurrent detection threshold before the camera starts operating.

9. 6. The electronic control device according to claim 5, wherein if it is determined that a communication abnormality has occurred after the camera has started operating, the camera power supply is restarted and the overcurrent detection unit detects an overcurrent again.

10. 10. The electronic control device according to claim 9, wherein, when the camera power supply is restarted, the overcurrent detection unit detects an overcurrent by restoring the overcurrent detection threshold from the changed threshold to the unchanged threshold.

11. 6. The electronic control unit according to claim 1, further comprising a communication unit (20z) that performs communication through the communication line with an error detection code added thereto and inhibits a write operation of the communication data after the communication is completed.

12. 6. The electronic control device according to claim 5, wherein the camera power supply is configured to be able to change its output voltage, and when starting up the camera and detecting an abnormality in the camera power supply, the output voltage is changed to a first predetermined voltage that does not reach the maximum rated power supply voltage of the camera, and before operating the camera normally, the output voltage is changed to a second predetermined voltage that is lower than the first predetermined voltage.

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