In-vehicle camera monitoring system

Abstract

To provide an in-vehicle camera monitoring system capable of detecting, even when a control unit is in a sleep mode, disconnection caused by unauthorized camera replacement.SOLUTION: In an in-vehicle camera monitoring system 1, an imaging signal from a camera 4 capturing images of an interior of a vehicle can be input to a microcomputer 6 that is compatible with a sleep mode. A voltage detection unit constituted of resistive elements 15-17 is disposed on a communication line 3b for inputting the imaging signal to the microcomputer 6, and detects voltage changes on the communication line 3b even when a vehicle ignition switch 9 is in an OFF state. When waking up from the sleep mode upon input of the detection signal from the voltage detection unit, the microcomputer 6 determines whether or not a disconnection operation has occurred on the communication line 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for monitoring a camera mounted on a vehicle for abnormalities. [Background technology]

[0002] Conventionally, one method for detecting abnormalities in a surveillance camera system is to provide a load monitoring function in the power supply device that monitors the operating status of the camera, as disclosed in Patent Document 1. In Patent Document 1, the load monitoring function monitors the load current of the camera, and when it detects a deviation from a specified value, it determines that an abnormality has occurred and activates an alarm device built into the power supply device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-19916 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above configuration assumes that the power is always on and the system is running. When the system is in standby or sleep mode, it is not monitored and no alarm is issued. For example, the ECU (Electronic Control Unit) installed in a vehicle switches the power on and off as needed. Therefore, when the power is off and the ECU is in standby mode, it cannot detect disconnections in the wiring or the replacement of the system with a hacking system.

[0005] Conversely, if a vehicle is to detect a disconnection using the configuration of Patent Document 1, the ECU must be kept constantly running. In this case, the lifespan of the ECU is shortened by keeping the power on all the time, which can lead to problems such as not meeting the specifications required by the manufacturer and battery failure due to increased current consumption.

[0006] The present invention has been made in consideration of the above circumstances, and its purpose is to provide an in-vehicle camera monitoring system that can detect a disconnection caused by unauthorized camera replacement even when the control unit is in sleep mode. [Means for solving the problem]

[0007] According to the in-vehicle camera monitoring system of claim 1, an image signal from a camera (4) capturing an image of the interior of the vehicle is input to a control unit (6) that is compatible with the sleep mode. Voltage detection units (15, 16) are arranged on a communication line (3b) that inputs the image signal to the control unit, and are configured to be able to detect voltage changes in the communication line even when the vehicle ignition switch (9) is in the OFF state. When the control unit wakes up from the sleep mode based on the detection signal input from the voltage detection unit, it determines that a disconnection operation has occurred in the communication line.

[0008] With this configuration, even if the control unit is in sleep mode, if someone cuts the communication line for inputting the image signal to the control unit, the voltage detection unit detects the corresponding change in voltage on the communication line and outputs a detection signal to the control unit. If the control unit wakes up in response to the input of the detection signal, it can determine that an operation to break the communication line has occurred.

[0009] According to the vehicle-mounted camera monitoring system of claim 2, the voltage detection unit comprises a first resistor element (15) connected between the communication line and a reference potential point on the camera side, and a second resistor element (16) having one end connected to a power source (8) supplied directly from the vehicle battery (7) and the other end connected to an input terminal (INT) for a signal that wakes up the control unit and the first resistor element via the communication line.

[0010] With this configuration, under normal conditions, the input terminal of the control unit is at a potential obtained by dividing the battery voltage, which is referenced to the reference potential point on the camera side, by the first and second resistor elements. If the communication line is disconnected, the input terminal is pulled up to the battery voltage via the first resistor element, causing a change in potential. If this change in potential is input to the control unit as a detection signal, the control unit will wake up and be able to determine that a disconnection operation has occurred.

[0011] According to the in-vehicle camera monitoring system of claim 3, the voltage detection unit includes a low-pass filter (19) whose input terminal is connected to the first resistor element via the communication line and whose output terminal is connected to the other end of the second resistor element, thereby preventing the control unit from waking up due to noise being applied to the communication line and falsely detecting a disconnection. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a functional block diagram illustrating the configuration of an in-vehicle camera monitoring system according to an embodiment of the present invention. [Figure 2] Diagram showing the layout of the in-vehicle camera monitoring system and the communication network with other ECUs [Figure 3] Flowchart showing the processing contents of the camera ECU DETAILED DESCRIPTION OF THE INVENTION

[0013] As shown in FIG. 1, the vehicle-mounted camera monitoring system 1 of this embodiment includes a camera ECU 2 mounted on a vehicle and a camera 4 connected to the camera ECU 2 via a communication line 3. As shown in FIG. 2, the camera 4 is located inside the vehicle, for example, above the steering wheel or near the rearview mirror, and is provided to mainly capture an image of the face of the driver of the vehicle. As shown in the same figure, the camera ECU 2 is located, for example, in the engine compartment or behind the dashboard. The microcomputer 6 constituting the camera ECU 2 corresponds to a control unit, and its operation mode can be switched between a sleep mode and a normal operation mode after waking up from the sleep mode.

[0014] The camera ECU 2 is equipped with an AWO (Always On) power supply circuit 8 that receives power directly from the vehicle's battery 7 and generates power for operating the microcomputer 6, and an ISO (Isolated On) power supply circuit 10 that receives power from the battery 5 via an ignition (IG) switch 9 and generates the operating power. The AWO power supply circuit 8 is used as a power supply for the microcomputer 6 in both sleep mode and normal operation mode, while the ISO power supply circuit 10 is used as a power supply only in normal operation mode. Power from the AWO power supply circuit 8 is also supplied to the camera 4.

[0015] The camera 4 is equipped with a camera signal output circuit 11 configured as an IC. The camera signal output circuit 11 is an IC known as a serializer, and has the function of serializing the digital signal of the image captured by the camera 4 and transmitting it to a camera signal input circuit 12 provided in the camera ECU 2. The camera signal output circuit 11 and the camera signal input circuit 12 are connected via coupling capacitors 13a and 13b, communication lines 3a and 3b, and capacitors 14a and 14b on the camera ECU 2 side.

[0016] Image data of the face of the driver, who is the legitimate owner of the vehicle, is pre-registered in a memory (not shown) of the microcomputer 6. When the microcomputer 6 receives image data transmitted from the camera 4, it compares the image data with pre-registered image data to authenticate the face of the driver. The microcomputer 6 also has a function to compare a one-time password entered via a mobile device such as a smartphone to authenticate the identity of the driver, as will be described in detail later.

[0017] On the camera 4 side, the communication line 3b is connected to the ground, which is a reference potential point, via a first resistor element 15. The microcomputer 6 has an INT terminal, which is an interrupt input terminal for detecting a break in the communication line 3. The INT terminal is connected to the power terminal of the AWO power supply circuit 8 via a second resistor element 16. On the camera ECU 2 side, the communication line 3b is connected to the ground via a resistor element 17 and a capacitor 18. These elements form a low-pass filter 19, and the output terminal of the low-pass filter 19 is connected to the INT terminal. The resistor elements 15 to 17 correspond to a voltage detection unit.

[0018] In the above state, the INT terminal of the microcomputer 6 is at a potential obtained by dividing the power supply voltage of the AWO power supply circuit 8 by the second resistor element 16 and the resistor elements 17 and 15. When the communication line 3b connecting the camera 4 and the camera ECU 2 is disconnected, the INT terminal, indicated as "Input A" in the figure, is pulled up to the power supply voltage of the AWO power supply circuit 8. When the communication line 3b is disconnected and the voltage at the INT terminal changes while the microcomputer 6 is in sleep mode, this is input as a detection signal, and the microcomputer 6 wakes up (starts up) and switches to normal operation mode. Note that, since the communication lines 3a and 3b are generally wired as a single harness, they are disconnected simultaneously. In other words, it is not assumed that only the communication line 3a will be disconnected.

[0019] 2, the camera ECU 2 also communicates with an engine ECU 21, a body ECU 22, and the like via an in-vehicle communication network such as a Controller Area Network (CAN; registered trademark). The engine ECU 21 controls engine-related devices 23 and determines whether to permit engine start through communication with the camera ECU 2. The body ECU 22 has a function of communicating with a smartphone 24 carried by the driver of the vehicle via Bluetooth (registered trademark).

[0020] Next, the operation of this embodiment will be described. The microcomputer 6 is initially in sleep mode. As shown in FIG. 3, when the ignition switch 9 is turned on and the ISO power supply circuit 10 supplies power for operation and starts up (S1; No), the microcomputer 6 performs face authentication by comparing the image data received from the camera 4 with pre-registered image data of the driver's face. If the authentication result is OK (S6; Yes), authentication is completed, and the microcomputer 6 communicates with the engine ECU 21 to permit engine start (S7). On the other hand, if the authentication result is NG (S6; No), authentication is not performed, and the microcomputer 6 communicates with the engine ECU 21 to prohibit engine start (S8).

[0021] As described above, if someone cuts the communication line 3, causing the voltage at the INT terminal to change and input A to become a trigger for activation (S1; Yes), there is a possibility that the system, including the on-board camera, has been replaced with an unauthorized one. Therefore, the microcomputer 6 locks the function without performing facial recognition (S2). Then, the microcomputer 6 communicates with the smartphone 24 carried by the driver of the vehicle via the body ECU 22 and requests the user to enter a one-time password (S3). If the one-time password sent and entered by the user using the dedicated app on the smartphone 24 matches a pre-registered password (S4; Yes), the microcomputer 6 unlocks the facial recognition function (S5). Then, the process proceeds to step S6.

[0022] If the entered one-time password does not match (S4; No), the process returns to step S3 and requests the user to enter the password again, provided that the number of mismatches is, for example, up to four (S9; No). If the number of mismatches reaches five (S9; Yes), the process ends. As described above, according to this embodiment, in the in-vehicle camera monitoring system 1, an imaging signal from the camera 4 capturing an image of the interior of the vehicle is input to the microcomputer 6 that is compatible with the sleep mode. A voltage detection unit made up of resistive elements 15 to 17 is disposed on the communication line 3b that inputs the imaging signal to the microcomputer 6, and detects voltage changes on the communication line 3b even when the vehicle ignition switch 9 is in the OFF state. When the microcomputer 6 wakes up from the sleep mode based on the detection signal input from the voltage detection unit, it determines that an operation to disconnect the communication line 3b has occurred.

[0023] With this configuration, even if the microcomputer 6 is in sleep mode, if someone cuts the communication line 3b for inputting an image signal to the microcomputer 6, the voltage detection unit detects the corresponding voltage change on the communication line 3b and outputs a detection signal to the microcomputer 6. The microcomputer 6 wakes up in response to the input of the detection signal, and is able to determine that an operation to cut the communication line 3 has occurred.

[0024] The voltage detection unit is composed of a first resistor element 15 connected between the communication line 3b and the ground on the camera 4 side, a second resistor element 16 having one end connected to the AWO power supply circuit 8 that is directly powered by the vehicle battery 7 and the other end connected to the first resistor element 15 via the input terminal INT of the microcomputer 6 and the communication line 3b, and a resistor element 17 that constitutes a low-pass filter 19.

[0025] Therefore, under normal conditions, the terminal INT of the microcomputer 6 has a potential obtained by dividing the voltage of the battery 7, with the ground on the camera 4 side as the reference potential, by the resistor element 16 and the resistor elements 17 and 15. If the communication line 3b is disconnected, the terminal INT is pulled up to the voltage of the battery 7 via the first resistor element 15, and the potential changes. When this potential change is input to the microcomputer 6 as a detection signal, the microcomputer 6 wakes up and can determine that a disconnection operation has occurred. In addition, the low-pass filter 19 prevents the microcomputer 6 from waking up due to noise being applied to the communication line 3, which could lead to a false detection of a disconnection.

[0026] Furthermore, when the microcomputer 6 determines that a disconnection operation has occurred, it stops the function of performing face authentication, so that if the system is replaced with a hacking system, it is possible to prevent face authentication from being performed fraudulently. Furthermore, when the microcomputer 6 determines that a disconnection operation has occurred, it communicates with the mobile terminal 24 held by the vehicle owner and requests the entry of a one-time password for personal authentication. Then, If the result of personal authentication is OK, the facial recognition function is enabled, and if the result is OK, the engine is allowed to start. This makes it possible to start the engine according to the results of personal authentication and facial recognition, even if the disconnection is not an unauthorized operation.

[0027] (Other embodiments) The low-pass filter 19 may be used as needed. That is, the voltage detection unit may be configured with only the first resistor element 15 and the second resistor element 16. Instead of a low-pass filter, the following configuration, for example, can be used. The INT terminal of the microcontroller is also used as the input terminal for A / D conversion. When there is a change in the potential of the INT terminal and the microcontroller wakes up from sleep mode, it starts the A / D conversion process and stores the converted data in memory for a certain period of time. The microcontroller then analyzes the changes in the stored data to determine whether there is a break in the wire or noise input.

[0028] The number of times the entered one-time passwords will not match may be changed as needed. Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various 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]

[0029] In the drawing, 1 indicates an in-vehicle camera monitoring system, 2 indicates a camera ECU, 3 indicates a communication line, 4 indicates a camera, 6 indicates a microcomputer, 7 indicates a battery, 8 indicates an AWO power supply circuit, 9 indicates an ignition switch, 15 indicates a first resistor element, 16 indicates a second resistor element, 19 indicates a low-pass filter, 23 indicates engine-related equipment, and 24 indicates a mobile terminal.

Claims

1. a camera (4) for capturing an image of the interior of the vehicle; A control unit (6) that receives an image signal from the camera and is compatible with a sleep mode; a voltage detection unit (15, 16) disposed in a communication line (3b) for inputting the imaging signal to the control unit, the voltage detection unit (15, 16) being configured to be able to detect a voltage change in the communication line even when an ignition switch (9) of the vehicle is in an OFF state; When the control unit wakes up from the sleep mode based on a detection signal input from the voltage detection unit, the control unit determines that a disconnection operation has occurred to the communication line.

2. The voltage detection unit includes a first resistor element (15) connected between the communication line and a reference potential point on the camera side; 2. The vehicle-mounted camera monitoring system of claim 1, further comprising: a second resistor element (16) having one end connected to a power source (8) supplied directly from the vehicle's battery (7) and the other end connected to an input terminal (INT) for a signal that wakes up the control unit and to the first resistor element via the communication line.

3. 3. The vehicle-mounted camera monitoring system according to claim 2, wherein the voltage detection unit includes a low-pass filter (19) having an input terminal connected to the first resistor element via the communication line and an output terminal connected to the other end of the second resistor element.

4. the control unit has a function of performing face authentication of an occupant of the vehicle based on the imaging signal, The vehicle-mounted camera monitoring system according to claim 1 , wherein when it is determined that the disconnection operation has occurred, the face authentication function is stopped.

5. The control unit has a function of communicating with a mobile terminal (24) owned by the owner of the vehicle, 5. The vehicle-mounted camera monitoring system according to claim 4, wherein when it is determined that the disconnection operation has occurred, a request for personal authentication is sent to the mobile terminal.

6. The control unit has a function of determining whether or not to start the engine (23) of the vehicle, If the result of the personal authentication performed via the mobile terminal is OK, the function of performing face authentication is enabled, The vehicle-mounted camera monitoring system according to claim 5, wherein the engine is permitted to start if the result of the face authentication is OK.

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