Dashboard camera and parking monitoring method

Abstract

To provide a dashboard camera and a parking monitoring method that enable recording of important images during parking without consuming battery power storage as much as possible.SOLUTION: A monitoring unit 11a monitors whether a vehicle has collided with another object. The monitoring unit 11a monitors collisions by use of a mechanical vibration switch 17 for parking monitoring detection that detects collisions by detecting mechanical vibrations, and an electronic circuit 19 that detects the operation of the mechanical vibration switch in terms of circuits.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a drive recorder and a parking monitoring method.

Background Art

[0002] Conventionally, a drive recorder has configured a parking monitoring system using a control device such as an acceleration sensor and a microcomputer, and records an image of the surrounding situation when an impact is detected on the vehicle body during parking (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of an engine using an internal combustion engine, the battery is charged by operating the internal combustion engine. Therefore, when the engine stops during parking, the charging of the battery also stops. Also, in the case of an electric vehicle or the like, the power supply from the battery of the electric vehicle stops while the vehicle is parked. For this reason, the drive recorder is powered by the battery. The drive recorder consumes operating current during parking monitoring. It is advisable to provide a power monitoring unit that monitors the battery voltage to protect the battery. In this case, the power monitoring unit may stop the parking monitoring function of the drive recorder on the condition that the battery voltage has dropped by a predetermined ratio (for example, 20%).

[0005] A large consumption current quickly consumes the stored power of the vehicle's battery, making it easier for the battery protection function to activate and the parking monitoring function to stop. For this reason, there is a risk that the video recording at the time of an accident cannot be obtained, which is not preferable.

[0006] An object of the present disclosure is to provide a drive recorder and a parking monitoring method that can record important images during parking without consuming the stored power of the battery as much as possible.

Means for Solving the Problems

[0007] According to the invention described in claim 1, a monitoring unit for monitoring whether the vehicle has collided with an object is provided. The monitoring unit monitors for collisions using a mechanical vibration switch for parking monitoring detection that detects a collision by detecting mechanical vibrations, and an electronic circuit that circuitously detects the operation of the mechanical vibration switch. Since the mechanical vibration switch detects the collision, important images during parking can be recorded without consuming the stored power of the battery as much as possible.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the drive recorder will be described with reference to the drawings. The drive recorder 1 shown in FIG. 1 is installed in a vehicle and records images around the vehicle using the camera 14. The drive recorder 1 is configured to record images around the vehicle, such as in front of, on the side of, and behind the vehicle, in the memory 12. In particular, the drive recorder 1 is configured to record images around the vehicle during driving, stopping, or parking of the vehicle, and store them in the memory 12.

[0010] As shown in FIG. 1, the drive recorder 1 includes a control device 11, a memory 12, an operation switch 13, a camera 14, an acceleration sensor 15, a power supply monitoring unit 16, a mechanical vibration switch 17, and a detection circuit 19. The control device 11 is mainly composed of a processor and is communicable with the memory 12. The memory 12 is composed of a volatile memory such as a RAM and a non-volatile memory such as a flash memory or an external memory, and is configured as a non-transitory physical recording medium. The control device 11 realizes various functions (for example, the functions of the monitoring unit 11a, the recording control unit 11b, and the diagnosis unit 11e) by executing the programs stored in the memory 12.

[0011] The operation switch 13 is composed of a mechanical switch or a touch panel that can be operated by a user of the vehicle. When the operation switch 13 is operated by the user, an operation signal is transmitted to the control device 11. The camera 14 is an imaging device that captures images of the surroundings of the vehicle and is installed facing the front, side, or rear of the vehicle. The camera 14 may be an omnidirectional camera. The camera 14 is used as a monitoring camera for monitoring whether the vehicle has collided with other objects such as other vehicles or obstacles. The camera 14 transmits the captured video signal to the control device 11.

[0012] The acceleration sensor 15 is mounted on the vehicle, detects the three-dimensional acceleration applied to the vehicle, and transmits an acceleration signal to the control device 11. When a power switch such as an ignition switch is turned on, power is supplied from the battery 10 to each device.

[0013] The control device 11 operates in the normal mode during normal driving or parking when the ignition switch is on, and operates in the parking monitoring mode when it is determined that the vehicle is parked. The control device 11 changes its operation according to the states of a plurality of modes including the normal mode and the parking monitoring mode. As a result, the power consumption of the control device 11 also changes according to the selected mode. In the parking monitoring mode, the control device 11 operates a small-scale circuit so as to suppress the power consumption lower than that in the normal mode.

[0014] During normal driving or when the vehicle is stopped, while power is being supplied to the acceleration sensor 15, the control device 11 functions as a driving operation monitoring unit 11c that monitors whether the vehicle has collided with another object based on the acceleration signal transmitted from the acceleration sensor 15 and the video signal transmitted from the camera 14.

[0015] Also, the control device 11 transitions to the parking monitoring mode on the condition that the ignition switch is off and IG does not turn on, and determines that the vehicle is parked. During parking of the vehicle, the control device 11 functions as a parking monitoring unit 11d that monitors for collisions using a mechanical vibration switch 17 for detecting collisions by detecting mechanical vibrations and a detection circuit 19 for circuitously detecting the operation of the mechanical vibration switch 17. The detection circuit 19 is equivalent to an electronic circuit.

[0016] Also, when the control device 11 determines that the vehicle has collided by the driving operation monitoring unit 11c or the parking monitoring unit 11d, it functions as a recording control unit 11b that controls recording of video in the memory 12. The control device 11 functions as a diagnostic unit 11e that diagnoses the operation of the mechanical vibration switch 17 while normally recording driving, and has a function to prevent malfunction.

[0017] The power supply monitoring unit 16 is connected to the battery 10, monitors the battery voltage V1, and notifies the control device 11 that the battery voltage V1 has dropped on the condition that it has dropped below a predetermined voltage. In this embodiment, the control device 11 continues the parking monitoring function even if the battery voltage V1 drops by a predetermined ratio.

[0018] The mechanical vibration switch 17 indicates a switch for detecting mechanical vibrations and impacts when the vehicle collides with another object. The mechanical vibration switch 17 has, for example, a normally open structure and normally maintains an off state, and is configured to turn on from the off state by detecting mechanical vibrations corresponding to a collision with another object or the like. When the mechanical vibration switch 17 detects vibrations, it turns on, and the detection circuit 19 detects this on operation.

[0019] Fig. 2 shows a configuration example of a mechanical vibration switch 17 and a detection circuit 19 for detecting its on / off state. A mechanical vibration switch 17 is connected to a battery 10. A detection circuit 19 is connected to the mechanical vibration switch 17. By detecting an input voltage Vin input through the mechanical vibration switch 17, the control device 11 checks for the presence or absence of an abnormal state of the mechanical vibration switch 17 and executes various controls in the normal mode or the parking monitoring mode.

[0020] The detection circuit 19 is configured by combining MOS transistors M1 to M3, resistors R1 to R6, and a diode D1. The MOS transistor M1 is constituted by, for example, a P-channel MOSFET, and the MOS transistors M2 and M3 are constituted by, for example, N-channel MOSFETs.

[0021] Between the voltage supply node N1 of the battery 10 and the ground, the drain-source of the MOS transistor M1 and the resistor R3 are connected in series. The source of the MOS transistor M1 and the resistor R3 are connected at the detection node N2 of the resistor R3. The detection node N2 of the resistor R3 is connected to the control device 11, and the voltage between the terminals of the resistor R3 is input to the control device 11.

[0022] Also, between the voltage supply node N1 and the ground, the mechanical vibration switch 17, the anode-cathode of the diode D1, and the resistors R6 and R2 are connected in sequence. Also, between the voltage supply node N1 and the ground, the resistor R1 and the drain-source of the MOS transistor M2 are connected in series.

[0023] Also, the common connection point of the resistors R6 and R2 is connected to the gate of the MOS transistor M2 and is connected to the detection node N2 through the resistor R4. The common connection point of the resistor R1 and the drain of the MOS transistor M2 is connected to the gate of the MOS transistor M1.

[0024] Also, between the common connection point of resistors R6 and R2 and the ground, the drain-source terminals of MOS transistor M3 are connected, and a resistor R5 is connected between the gate-source terminals of MOS transistor M3. The reset signal RESET can be applied from the control device 11 to the gate of MOS transistor M3. This reset signal RESET indicates a signal for resetting the gate potential of MOS transistor M2 to zero.

[0025] The input voltage Vin shown in FIG. 2 is the voltage V1 of the battery 10 that is energized through the node N1 while the mechanical vibration switch 17 is on. If the mechanical vibration switch 17 is on, the input voltage Vin becomes the same level as the voltage V1, and if the mechanical vibration switch 17 is off, the input voltage Vin is connected to the ground through the resistors R2 and R6 and thus becomes zero V.

[0026] <Operation of the detection circuit 19 when the mechanical vibration switch 17 is off> Normally, the mechanical vibration switch 17 remains off and is in an open state. In this state, the gate of MOS transistor M2, together with the detection node N2, is at the ground potential. Therefore, MOS transistor M2 can maintain the off state. Also, since the voltage between the gate and source of MOS transistor M1 becomes zero, MOS transistor M1 maintains the off state.

[0027] Since the mechanical vibration switch 17 mechanically cuts off the input and output, no current flows in principle. Therefore, the detection circuit 19 consumes only the subthreshold leakage current flowing when MOS transistor M1 is off. By adopting this configuration of the detection circuit 19, the current consumption of most of the circuit configurations in the detection circuit 19 can be made zero, and the current consumption of the detection circuit 19 can be significantly suppressed.

[0028] The control device 11 detects the on / off state of the mechanical vibration switch 17 by inputting the voltage across the terminals of the resistor R3 to a comparator. The control device 11 compares a predetermined threshold voltage with the detected voltage of the resistor R3, and if it is lower, determines that the mechanical vibration switch 17 is in the off state. Since the voltage across the terminals of the resistor R3 is zero, the control device 11 determines that the mechanical vibration switch 17 is in the off state.

[0029] <Operation of the detection circuit 19 when the mechanical vibration switch 17 is turned on> The mechanical vibration switch 17 turns on when it detects vibration due to some influence such as the vehicle traveling on a road where vibration is detected or colliding with an object. When the mechanical vibration switch 17 turns on, the battery voltage V1 is applied to the diode D1, resistors R6 and R2 through the node N1. Then, current flows through the diode D1, resistors R6 and R2, and the voltage across the terminals of the resistor R2 increases. Then, the gate-source voltage of the MOS transistor M2 increases, and when it exceeds the threshold voltage, the MOS transistor M2 turns on.

[0030] When the MOS transistor M2 turns on, current flows through the resistor R1 and between the drain and source of the MOS transistor M2, and the gate potential of the MOS transistor M1 decreases by the voltage across the terminals of the resistor R1. When the gate-source voltage of the MOS transistor M1 exceeds the threshold voltage, the MOS transistor M1 turns on, and current flows from the node N1 through the node N2 into the resistor R3, and the voltage across the terminals of the resistor R3 increases.

[0031] Then, the control device 11 can determine that the mechanical vibration switch 17 has turned on. Here, the detection circuit 19 is configured as shown in FIG. 2, but this is not the only case. As long as the power consumption of the mechanical vibration switch 17 during detection standby is low, the on / off state can be detected in any way.

[0032] <Operation explanation> Referring to FIG. 3, the operations in the normal mode and the parking monitoring mode will be described. The diagnosis unit 11e of the control device 11 diagnoses the operation of the mechanical vibration switch 17, particularly the presence or absence of OFF sticking of the mechanical vibration switch 17, during normal ignition switch ON and vehicle running in S1 to S3. For example, when the ignition switch is ON and the vehicle is running on the road, the vehicle vibrates. If the mechanical vibration switch 17 is operating normally, the mechanical vibration switch 17 turns ON when it detects vibration. When the vibration of the vehicle subsides, the mechanical vibration switch 17 turns OFF.

[0033] While the vehicle is running on the road, each time the vehicle vibrates, the mechanical vibration switch 17 repeats ON / OFF. At this time, the control device 11 sequentially records the ON history of the mechanical vibration switch 17 in the memory 12 at S2 in FIG. 3. The control device 11 can detect that the mechanical vibration switch 17 switches from OFF to ON due to the action of the detection circuit 19 in response to the mechanical vibration switch 17 detecting vibration, and can diagnose that the mechanical vibration switch 17 is not stuck OFF at S3. If the mechanical vibration switch 17 does not turn ON even when the vehicle vibrates, no ON history remains in the memory 12. Therefore, the control device 11 can determine whether the mechanical vibration switch 17 is stuck OFF by checking the presence or absence of the ON history of the mechanical vibration switch 17 in the memory 12.

[0034] Also, when the vehicle stops and the ignition switch is turned OFF, the vibration generated in the vehicle also stops. As a result, the mechanical vibration switch 17 transitions to the OFF state. If the mechanical vibration switch 17 is operating normally, since the mechanical vibration switch 17 turns OFF, the gate of the MOS transistor M2 becomes the ground potential and the potential of the node N2 becomes the ground potential. Conversely, if the mechanical vibration switch 17 is stuck ON, the mechanical vibration switch 17 is maintained in the ON state, so the potential of the node N2 remains at a high potential.

[0035] If the control device 11 detects the detection voltage Vout of the detection circuit 19 and it has dropped to ground or a nearby potential, it records the off history of the mechanical vibration switch 17 in the memory 12 at S4 in FIG. 3. By referring to the off history recorded in the memory 12, the control device 11 diagnoses whether the mechanical vibration switch 17 is stuck on at S5.

[0036] If the mechanical vibration switch 17 does not turn off even when the vibration stops, no off history remains in the memory 12. Therefore, the control device 11 can determine whether the mechanical vibration switch 17 is stuck on by checking the memory 12 for the presence or absence of the off history of the mechanical vibration switch 17 from the timing when the ignition switch was turned off.

[0037] In this way, the control device 11 can check whether the mechanical vibration switch 17 is operating normally by using the vibration conditions when the vehicle is running and when it is stopped. When an abnormality is found in the diagnosis of the mechanical vibration switch 17, the control device 11 determines that the diagnosis result is abnormal at S6, records an error log at S7, and issues an alert at S8 and then ends.

[0038] Conversely, when the diagnosis unit 11e of the control device 11 determines at S6 that the mechanical vibration switch 17 is operating normally, it starts the parking monitoring mode at S9.

[0039] The control device 11 collects the vibration conditions by the mechanical vibration switch 17 and the detection circuit 19 at S10, and continues to check at S11 whether the mechanical vibration switch 17 has received an impact. If the control device 11 does not detect an impact, it returns the process to S10. Also, when the control device 11 confirms an impact at S11, it starts recording parking video data in the memory 12 at S12.

[0040] When the control device 11 starts recording parking recording data in the memory 12, it starts timer measurement and determines whether or not a predetermined timer setting time has elapsed in S14. If the control device 11 determines in S14 that the timer setting time has not elapsed, it returns the process to S12 and continues recording the parking recording data in the memory 12. While these S12 and S14 are being executed, in S13, an off history indicating whether or not the mechanical vibration switch 17 is off is recorded in the memory 12.

[0041] When the timer setting time has elapsed, the control device 11 stops recording the parking recording data to the memory 12 in S15. Thereby, the video serving as accident evidence can be surely recorded and the recording can be guaranteed.

[0042] The control device 11 continues to record in the memory 12 an off history indicating whether or not the mechanical vibration switch 17 is off before and after being subjected to an impact. For this reason, after the timer setting time has elapsed, it is possible to diagnose whether or not the mechanical vibration switch 17 is stuck on, and it is possible to determine whether or not the mechanical vibration switch 17 is operating normally even after being subjected to an impact.

[0043] Also, the control device 11 continues to record the off history of the mechanical vibration switch 17 in the memory 12 in S13, and diagnoses whether or not it is stuck on in S6 even after the recording is stopped in S15. In this case, it is possible to prevent an infinite loop of parking recording caused by a malfunction of the mechanical vibration switch 17 and prevent the battery from running out.

[0044] <Comparison with a comparison target> FIG. 4 shows the configuration of a comparison target. In the configuration of FIG. 4 of the comparative example, a collision was detected without providing the mechanical vibration switch 17. However, since it consumes a large amount of current, it has been desired to suppress the current consumption as much as possible.

[0045] <Summary of this embodiment> According to this embodiment, at the time of parking, a mechanical vibration switch 17 and a detection circuit 19 are used to detect a collision. Therefore, compared with the prior art, a significant reduction in current consumption can be achieved, thereby reducing the consumption of the stored power of the battery 10. The current consumption during parking can be suppressed to, for example, about 1 μA, and the video at the time of an accident can be recorded for as long as possible.

[0046] According to the configuration of this embodiment, since the current consumption can be significantly reduced, the consumption of the stored power of the battery 10 can be minimized. Since the current consumption can be suppressed to the limit, the function stop due to the protection function of the battery 10 can be prevented as much as possible, the loss of the video which is an important accident evidence can be prevented, and the securing of the accident evidence can be strengthened.

[0047] The detection circuit 19 includes a MOS transistor M1 that turns off when the mechanical vibration switch 17 does not detect a collision and turns on when the mechanical vibration switch 17 detects a collision. When no collision is detected, the detection circuit 19 is configured to consume only the subthreshold leakage current flowing when the MOS transistor M1 is in the off state. As a result, the power consumption during standby can be suppressed, the power of the battery 10 can be managed with high efficiency, and the parking monitoring can be maintained for a long time.

[0048] The control device 11 has a function of a diagnosis unit 11e that diagnoses the operation of the mechanical vibration switch 17 by using the vibration conditions when the vehicle is running and when it is stopped, and has a malfunction prevention function. As a result, the video that becomes accident evidence can be surely recorded and the recording can be guaranteed. As a result, data loss due to malfunction can be prevented. In addition, it is possible to prevent the battery from running out due to an infinite loop of parking recording caused by a malfunction of the mechanical vibration switch 17.

[0049] (Other embodiments) The present invention is not limited to the foregoing embodiments, and for example, the following modifications or extensions are possible. The detection circuit 19 has been described as using MOS transistors M1 and M2, but is not limited thereto and may be configured using other semiconductor switching elements such as bipolar transistors. Also, although an example of the configuration of the detection circuit 19 is shown in Fig. 2, the circuit configuration is not limited to that shown in Fig. 2 as long as the on / off operation of the mechanical vibration switch 17 can be detected in a circuit manner.

[0050] The techniques described in the present disclosure may be implemented by a special purpose computer provided by configuring a processor and memory 12 programmed to perform one or more functions embodied in a computer program. Alternatively, the techniques described in the present disclosure may be implemented by a special purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the techniques described in the present disclosure may be implemented by one or more special purpose computers configured by a combination of a processor and memory 12 programmed to perform one or more functions and a processor configured with one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible storage medium as instructions executed by the computer.

[0051] Although the present disclosure has been described based on the above-mentioned 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 includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0052] In the drawing, 11a denotes a monitoring section, 11e denotes a diagnostic section, 17 denotes a mechanical vibration switch, 19 denotes a detection circuit (electronic circuit), and M1 denotes a MOS transistor (semiconductor switching element).

Claims

1. A drive recorder comprising a monitoring unit (11a) that monitors whether or not the vehicle has collided with an object during parking, wherein the monitoring unit uses a mechanical vibration switch (17) for parking monitoring detection that detects a collision by detecting mechanical vibration, and an electronic circuit (19) that circuitously detects the operation of the mechanical vibration switch to monitor the collision.

2. The electronic circuit of the monitoring unit includes a semiconductor switching element (M1) that turns off when the mechanical vibration switch does not detect a collision and turns on when the mechanical vibration switch detects a collision, The drive recorder according to claim 1, wherein when the collision is not detected, the semiconductor switching element is configured to consume only a sub-threshold leakage current that flows in the off state.

3. The drive recorder according to claim 1 or 2, further comprising a diagnostic unit (11e) that diagnoses the operation of the mechanical vibration switch by using the vibration conditions when the vehicle is running and when it is stopped.

4. When the monitoring unit (11a) monitors whether or not the vehicle has collided with an object during parking, A parking monitoring method in which a mechanical vibration switch (17) for parking monitoring detection detects a collision by detecting mechanical vibration, and an electronic circuit (19) circuitously detects the operation of the mechanical vibration switch to monitor the collision.

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