JP2019149091A - On-vehicle device, control method for on-vehicle device, and program - Google Patents

Abstract

To provide an on-vehicle device that can maintain on-vehicle device functions according to necessity.SOLUTION: The on-vehicle device includes: a plurality of functional units that execute on-vehicle device functions different from each other; a power supply unit that supplies electric power received from a battery of a vehicle to the plurality of functional units; a voltage detection unit that outputs a voltage reduction detection signal indicating a reduction in voltage of electric power; and an electric power supply selection unit that selects a functional unit that maintains execution of the on-vehicle device functions from among the plurality of functional units, and in a case where the voltage reduction detection signal is output from the voltage detection unit, maintains supply of electric power to the selected functional unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an on-vehicle device, an on-vehicle device control method, and a program.

  In a vehicle, for example, when the power unit changes to an idling state, the output voltage of the battery may temporarily drop. At this time, in the vehicle-mounted device, a supply voltage to a functional unit such as a wireless communication unit that wirelessly communicates with the roadside device may be insufficient, and the vehicle-mounted device function may not be maintained.

  In Patent Document 1, when the on-chip one-chip microcomputer detects a decrease in internal voltage, it stops all operations except card detection, and when the internal voltage is restored without removing the ETC card, It is described that the narrow-area communication with the ETC roadside device is resumed based on the card information on the assumption that the card information stored in is valid.

Japanese Patent No. 5994660

  However, since the process for maintaining communication is not performed in the above-mentioned Patent Document 1, there is a possibility that communication is temporarily interrupted, initial processing becomes necessary again, or a communication error occurs. In addition, there is a similar risk in other functional units such as a GPS receiver.

  The present invention has been made in view of the above problems, and a main object thereof is to provide an on-vehicle device capable of maintaining the on-vehicle device function as required, a control method for the on-vehicle device, and a program. It is in.

  In order to solve the above problems, the vehicle-mounted device according to one aspect of the present invention includes a plurality of functional units that execute different vehicle-mounted device functions, and a power supply unit that supplies power received from a vehicle battery to the plurality of functional units. A voltage detection unit that outputs a voltage drop detection signal indicating a drop in the power voltage, and a function unit that maintains execution of the vehicle-mounted device function is selected from the plurality of function units, and the voltage detection unit A power supply selection unit that maintains power supply to the selected functional unit when the voltage drop detection signal is output.

  Moreover, the control method for the vehicle-mounted device according to another aspect of the present invention includes a plurality of functional units that execute different vehicle-mounted device functions, a power supply unit that supplies power received from a vehicle battery to the plurality of functional units, A voltage drop detection signal indicating a drop in the power voltage, selecting a functional unit that maintains execution of the on-vehicle device function from the plurality of functional units, When the voltage drop detection signal is output, power supply to the selected functional unit is maintained.

  A program according to another aspect of the present invention includes a plurality of function units that execute different vehicle-mounted device functions, a power supply unit that supplies power received from a battery of a vehicle to the plurality of function units, and a voltage of the power A voltage detection unit that outputs a voltage drop detection signal indicating a decrease in the voltage of the vehicle-mounted device, selecting a functional unit that maintains execution of the vehicle-mounted device function from the plurality of functional units, and detecting the voltage When the voltage drop detection signal output from the unit is output, the voltage drop detection signal is made to function as a power supply selection unit that maintains power supply to the selected functional unit.

  According to the present invention, it is possible to maintain a vehicle-mounted device function as required.

It is a block diagram which shows the structural example of the onboard equipment which concerns on embodiment. It is a block diagram which shows the structural example which concerns on the electric power supply of the said onboard equipment. It is a functional block diagram which shows the example of a function which the said onboard equipment implement | achieves. It is a flowchart which shows the process example which the said onboard equipment performs. It is a timing diagram which shows the operation example of the said onboard equipment. It is a timing diagram which shows the operation example of the said onboard equipment. It is a timing diagram which shows the operation example of the said onboard equipment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, each embodiment shown below illustrates the method and apparatus for actualizing the technical idea of this invention, Comprising: The technical idea of this invention is not necessarily limited to the following. Absent. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

  FIG. 1 is a block diagram illustrating a configuration example of the vehicle-mounted device 1 according to the embodiment. The vehicle-mounted device 1 is an ETC vehicle-mounted device used in an electronic fee collection system (ETC: Electronic Toll Collection System). The vehicle-mounted device 1 wirelessly communicates with roadside devices provided at entrances and the like of toll roads and exchanges information such as tolls. The vehicle-mounted device 1 is mounted on a vehicle and operates by receiving power supply from the battery 400 of the vehicle.

  The vehicle-mounted device 1 includes a control unit 10, a storage unit 12, a power supply circuit 2, a voltage detection unit 26, a device communication unit 3, a wireless communication unit 4, a GNSS reception unit 5, a light emitting unit 6, an audio output unit 7, and an operation input unit 8. , A functional unit monitoring unit 14, a card holder 9, a card detection unit 92, and a forgetting to remove notification unit 94. The control unit 10 includes at least one microprocessor (CPU) and executes information processing according to a program stored in the storage unit 12. The storage unit 12 includes a main storage unit (for example, RAM) and an auxiliary storage unit (for example, a nonvolatile semiconductor memory).

  The power supply circuit 2 supplies power from the vehicle battery 400 to each part of the vehicle-mounted device 1. An example of a power supply configuration in the vehicle-mounted device 1 will be described later. In the present embodiment, the power supply connection format of the power supply circuit 2 is, for example, a two-wire system, and the accessory power supply line (ACC) and the ground line (GND) are connected to the power supply circuit 2 via the power supply connector 21. Yes. That is, the power supply circuit 2 is not always connected to the power supply line. However, the power connection format is not limited to this, and may be a three-wire system that always includes a power supply line in addition to the accessory power supply line and the ground line. Here, the power connector 21 and the power circuit 2 may be collectively referred to as a power supply unit 20. The power supply unit 20 may include a vehicle battery 400. Note that the power supply unit 20 may be configured only from a battery, and power may be directly supplied from the battery.

  The device communication unit 3 is a functional unit that communicates with other devices inside or outside the vehicle. Specifically, the device communication unit 3 is an interface circuit, and is connected to other devices in the vehicle such as a car navigation device via an I / F connector 32 in accordance with, for example, the RS-232C standard. For example, the device communication unit 3 may wirelessly communicate with other devices inside and outside the vehicle, for example, by a wireless LAN.

  The wireless communication unit 4 is a functional unit that performs wireless communication with a roadside device. The wireless communication unit 4 includes a high frequency circuit and is connected to the antenna 45 via the antenna connector 43. The wireless communication unit 4 performs predetermined signal processing on the signal received by the antenna 45, outputs the generated information to the control unit 10, performs predetermined signal processing on the information from the control unit 10, and outputs the generated signal. Output to the antenna 45. The signal processing by the wireless communication unit 4 is performed in accordance with, for example, a DSRC (Dedicated ShortRange Communication) standard.

  The GNSS receiving unit 5 is a functional unit that receives radio waves from a GNSS (Global Navigation Satellite System). The GNSS receiver 5 is, for example, a GPS receiver. The GNSS receiving unit 5 calculates the current position based on the radio wave received from the GNSS, and outputs information on the current position to the control unit 10. The GNSS receiving unit 5 is connected to the antenna 45 via the antenna connector 43, similarly to the wireless communication unit 4.

  The light emitting unit 6 is a functional unit for notifying the state of the vehicle-mounted device 1. The light emitting unit 6 includes, for example, an LED and a drive circuit, and the drive circuit drives the LED in response to a command from the control unit 10. The voice output unit 7 is a functional unit for outputting guidance voice. The audio output unit 7 includes, for example, a speaker and an audio circuit, and the audio circuit drives the speaker in response to a command from the control unit 10. The operation input unit 8 is a functional unit that receives an operation input from a user. The operation input unit 8 is, for example, a button switch. In addition to the button switch, the operation input unit 8 may be, for example, a slide switch or an operation controller, and is configured to accept an external operation input (input of an external operation signal). Also good.

  The card detection unit 92 detects that an ETC card is inserted in the card holder 9. The card detection unit 92 includes, for example, a card detection circuit, and outputs a detection signal indicating the presence / absence of an ETC card in the card holder 9 to the control unit 10 and the forgetting to remove notification unit 94. The card detection unit 92 determines the presence / absence of an ETC card based on, for example, the state of a switch that detects insertion of an ETC card provided in the card holder 9.

  The forgetting to remove notification unit 94 includes a warning sound generation circuit, and when the ETC card is still inserted in the card holder 9 when the accessory power supply is turned off, based on the detection signal from the card detection circuit 22. Outputs a warning sound forgetting to unplug.

  FIG. 2 is a block diagram illustrating a configuration example relating to power supply of the vehicle-mounted device 1. In the figure, the wireless communication unit 4 and the GNSS receiving unit 5 are illustrated as an example among a plurality of functional units that receive power supply. The power supply unit 20 steps down the voltage from the vehicle battery 400 and supplies the stepped down voltage to each unit of the vehicle-mounted device 1. The power supply unit 20 is, for example, a DC / DC converter. In the following description, the stepped down voltage downstream of the power supply unit 20 is referred to as “internal voltage”, and the voltage not stepped down upstream of the power supply unit 20 is referred to as “external voltage”.

  Each of the control unit 10, the wireless communication unit 4, and the GNSS reception unit 5 is provided with a voltage adjustment unit 23 that adjusts the internal voltage. The voltage adjustment unit 23 is, for example, a linear regulator. Each of the voltage adjusting units 23 steps down the internal voltage to voltages suitable for the operations of the control unit 10, the wireless communication unit 4, and the GNSS receiving unit 5. The voltage adjustment unit 23 may also be provided in the device communication unit 3, the light emitting unit 6, the audio output unit 7, the operation input unit 8, and the like.

  Each of the control unit 10, the wireless communication unit 4, and the GNSS reception unit 5 is also provided with a switching unit 25 that switches connection and disconnection of the auxiliary power source. In the present embodiment, the power upstream of the power supply unit 20 is used as an auxiliary power supply. That is, each of the switching units 25 is connected upstream of the power supply unit 20 and switches between connection and disconnection of the external voltage. The switching unit 25 may also be provided in the device communication unit 3, the light emitting unit 6, the audio output unit 7, the operation input unit 8, and the like.

  The switching unit 25 includes a switching element such as a power MOSFET, for example. Furthermore, the switching unit 25 may include a booster (transformer) that boosts the external voltage. The booster is, for example, a switching regulator. Each of the switching units 25 is controlled by the control unit 10. Control of the switching unit 25 by the control unit 10 will be described later.

  The voltage detection unit 26 includes an internal voltage detection unit 27 that detects an internal voltage downstream of the power supply unit 20, an external voltage detection unit 28 that detects an external voltage upstream of the power supply unit 20, and a logic operation unit 29. Yes. The internal voltage detection unit 27 includes, for example, a voltage detection circuit, and outputs a voltage drop detection signal when the internal voltage falls below a predetermined threshold. The external voltage detection unit 28 includes, for example, a voltage detection circuit, and outputs a voltage drop detection signal when the external voltage falls below a predetermined threshold. The logical operation unit 29 includes, for example, an AND circuit, and outputs a logical product of the voltage drop detection signals from the internal voltage detection unit 27 and the external voltage detection unit 28 to the control unit 10. Instead of using an AND circuit as the logical operation unit 29, logical product processing by software or the like may be used.

  By the way, in a vehicle, when a power unit such as an engine or a motor changes to an idling state, the output voltage of the battery 400 may temporarily drop. At this time, in the vehicle-mounted device 1, there is a possibility that the internal voltage supplied to the functional units such as the wireless communication unit 4 and the GNSS receiving unit 5 may be insufficient. Therefore, in the present embodiment, as will be described below, processing for maintaining a predetermined on-vehicle device function is executed.

  For example, if the output voltage of the battery 400 temporarily drops, the forgetting to pull out notification unit 94 (see FIG. 1) may be activated, and the forgetting to pull out warning sound may be output in the same manner as when the accessory power supply is turned off. Therefore, in the present embodiment, as will be described below, processing for limiting a predetermined on-vehicle device function is also executed.

  Here, the idling state refers to a state where the power unit does not contribute to the propulsion of the vehicle but can contribute immediately. In a vehicle including an engine in the power unit, the engine may be temporarily stopped when the engine is changed to an idling state (so-called idling stop), and at that time, the output voltage of the battery 400 may be greatly reduced temporarily. Further, in a vehicle including a motor in the power unit, the output voltage of the battery 400 may temporarily greatly decrease as the power consumption of the motor decreases.

  FIG. 3 is a functional block diagram mainly showing functions related to the present invention among the functions realized by the vehicle-mounted device 1. The vehicle-mounted device 1 includes a voltage detection unit 26, a function unit monitoring unit 14, a power supply selection unit 102, a restriction unit 107, an authentication unit 109, a plurality of switching units 25, a plurality of function units 200, and an auxiliary power supply 300. .

  Among these, the power supply selection unit 102, the restriction unit 107, and the authentication unit 109 are functional blocks that are realized when the control unit 10 executes information processing according to a program stored in the storage unit 12. Note that the functional unit monitoring unit 14 may also be a functional block realized in the control unit 10 (may be a functional unit).

  The plurality of functional units 200 are a device communication unit 3, a wireless communication unit 4, a GNSS receiving unit 5, a light emitting unit 6, an audio output unit 7, an operation input unit 8, and the like (see FIG. 1), and have different in-vehicle device functions. Run. Each functional unit 200 is provided with a switching unit 25 that switches between connection and disconnection of the auxiliary power supply 300. The control unit 10 is also provided with a switching unit 25.

  The voltage detection unit 26 monitors the output voltage of the battery 400, that is, the input voltage (internal voltage or external voltage) of the vehicle-mounted device 1, and when the input voltage falls below a predetermined threshold value, a voltage drop detection signal is supplied to the power supply selection unit. 102 and the limiting unit 107. As the threshold value, for example, a first threshold value for detecting a drop in input voltage and a second threshold value for detecting a change to an idling state that is lower than the first threshold value are used. In the present embodiment, an internal voltage detection threshold (first threshold and second threshold) and an external voltage detection threshold (first threshold and second threshold) are prepared.

  In the present embodiment, a voltage drop detection signal output by the internal voltage detection unit 27 when the internal voltage falls below a predetermined threshold value, and a voltage output by the external voltage detection unit 28 when the external voltage falls below a predetermined threshold value. A logical sum with the drop detection signal is used (see FIG. 2). The external voltage is suitable for detecting a voltage drop because the drop width is larger than the internal voltage. The internal voltage is suitable for detecting an accurate voltage value. Therefore, by monitoring both the internal voltage and the external voltage, it is possible to detect an accurate voltage value while quickly detecting a voltage drop.

  It should be noted that the present invention is not limited to the mode using the logical sum, and for example, only one of the internal voltage and the external voltage may be monitored. For example, when detecting a drop in the input voltage, the external voltage is monitored and idling is performed. When detecting the change to the state, the internal voltage may be monitored.

  The functional unit monitoring unit 14 monitors the states of the plurality of functional units 200 and outputs a determination signal indicating whether or not each on-board unit function is executed in each functional unit 200 to the power supply selection unit 102.

  The power supply selection unit 102 selects the functional unit 200 that maintains execution of the vehicle-mounted device function from among the plurality of functional units 200 according to the monitoring result by the functional unit monitoring unit 14. Specifically, the power supply selection unit 102 selects the function unit 200 when receiving a voltage drop detection signal from the voltage detection unit 26 indicating that the input voltage has fallen below the first threshold for voltage drop detection. Start. The power supply selection unit 102

  For example, the power supply selection unit 102 selects the functional unit 200 in an execution state from the plurality of functional units 200 based on the determination signal from the functional unit monitoring unit 14. That is, when the wireless communication unit 4 is establishing a communication link with the roadside device, the wireless communication unit 4 is selected, and when the GNSS receiving unit 5 is in the positioning state, the GNSS receiving unit 5 is selected and the voice output is performed. When the unit 7 is outputting audio, the audio output unit 7 is selected.

  In addition, the power supply selection unit 102 selects a functional unit 200 having a predetermined priority level or higher from a plurality of functional units 200 based on the priorities of execution of the in-vehicle device functions in each functional unit 200 stored in advance. May be. In addition, the power supply selection unit 102 selects a function 200 unit with power consumption of a predetermined value or less from the plurality of function units 200 based on the power consumption under execution of the vehicle-mounted device function in each function unit 200 stored in advance. You may choose.

  The power supply selection unit 102 detects that the power unit of the vehicle has changed to an idling state. In the present embodiment, based on the voltage drop detection signal from the voltage detection unit 26, a change to the idling state is detected. Specifically, when the power supply selection unit 102 receives from the voltage detection unit 26 a voltage drop detection signal indicating that the input voltage has fallen below the second threshold for state change detection, the power supply unit of the vehicle is in an operating state. It is detected that the state has changed from idling to idling.

  The output of the voltage drop detection signal representing the change to the idling state is not limited to this, and may be performed, for example, by monitoring the vehicle speed (receiving the vehicle speed signal), or idling in an in-vehicle communication network such as CAN. It may be performed by monitoring information (receiving data related to the idling state), may be performed by acquiring information on traffic lights, etc., or monitoring a vehicle front image captured by an in-vehicle camera May be performed by receiving analysis data of the vehicle front image.

  The power supply selection unit 102 maintains power supply to the selected function unit 200 when it is detected that the state has changed to the idling state. Specifically, the power supply selection unit 102 connects the selected functional unit 200 to the auxiliary power supply 300 by driving the switching unit 25 corresponding to the selected functional unit 200. Thereby, it becomes possible to maintain the onboard equipment function as needed.

  In this embodiment, since the upstream of the power supply circuit 2 is used as the auxiliary power supply 300 (see FIG. 2), an external voltage is supplied to the selected function unit 200. Since the external voltage is not stepped down by the power supply circuit 2 and is higher than the internal voltage, it is suitable for maintaining power supply. In particular, when the switching unit 25 includes a booster, the external voltage can be boosted and supplied to the functional unit 200 even if the external voltage drops significantly.

  The power supply selection unit 102 also maintains power supply to the control unit 10 when it is detected that the state has changed to the idling state. Specifically, the power supply selection unit 102 connects the control unit 10 to the auxiliary power supply 300 by driving the switching unit 25 provided in the control unit 10. Thereby, execution of the function of the power supply selection unit 102 itself is also maintained. Further, the execution of the function of the authentication unit 109 that executes the ETC card authentication process is also maintained.

  When the power supply selection unit 102 detects that the restriction unit 107 has changed to the idling state, the restriction unit 107 restricts execution of a specific on-vehicle device function. Specifically, the restriction unit 107 restricts notification of forgetting to remove the ETC card when the state changes to an idling state. As a result, it is possible to prevent a warning sound that is forgotten to be removed every time the idling state is changed.

  FIG. 4 is a flowchart showing an example of processing executed by the vehicle-mounted device 1. When the control unit 10 executes the processing shown in FIG. 4 according to the program, the control unit 10 functions as the power supply selection unit 102, the restriction unit 107, and the authentication unit 109 shown in FIG. 5 to 7 are timing diagrams illustrating an operation example of the vehicle-mounted device 1. FIG.

  First, when the accessory power supply of the vehicle is turned on and the input voltage exceeds a first threshold value (for example, 12V as an internal voltage) (S11), the control unit 10 executes an initial operation and a card authentication process, and performs an initial operation result and a card. The completion of authentication is notified (S12, S13). The notification is performed by outputting sound from the sound output unit 7. The execution of the card authentication process and the notification of the completion of the card authentication are processes for realizing the authentication unit 109.

  Next, the control unit 10 performs normal operation while the input voltage is equal to or higher than the first threshold (S14: NO) (S26). On the other hand, when the input voltage falls below the first threshold (S14: YES), the controller 10 proceeds to a selection process (S15-S17) described below. The first threshold value is a threshold value for detecting a drop in input voltage.

  In the selection process (S15-S17), the control unit 10 determines whether or not the GPS positioning state is established and whether or not the communication link is being established. The selection process (S15-S17) is a process for realizing the power supply selection unit 102. As a result, a functional unit that maintains power supply is selected. Note that the control unit 10 is always a target for maintaining power supply.

  The GPS positioning state refers to a state where the current position is calculated based on GPS radio waves received from a satellite or the like. Establishing the communication link indicates that the vehicle-mounted device 1 and the roadside device are in a state where communication is possible by exchanging identification information and time information with each other.

  When it is not in the GPS positioning state and the communication link is not established (S15: NO, S16: NO), only the control unit 10 is selected.

  When the communication link is being established without being in the GPS positioning state (S15: NO, S16: YES), the control unit 10 and the wireless communication unit 4 are selected.

  When in the GPS positioning state and the communication link is not established (S15: YES, S17: NO), the control unit 10 and the GNSS receiving unit 5 are selected.

  When the GPS positioning state is established and the communication link is being established (S15: YES, S17: YES), the control unit 10, the wireless communication unit 4, and the GNSS receiving unit 5 are selected.

  Next, when the control unit 10 detects that the input voltage has fallen below a second threshold (for example, 5 V as an internal voltage) (S18: YES), the control process (S19) and the maintenance process (S20-S23) described below are performed. ). The second threshold value is a threshold value for detecting a change to the idling state. By detecting that the input voltage has fallen below the second threshold, it is detected that the input voltage has changed to the idling state. That is, the detection of the change to the idling state is a process for realizing the power supply selection unit 102.

  Note that while the input voltage exceeds the second threshold (S18: NO), the control unit 10 maintains normal operation (S26).

  In the restriction process (S19), the control unit 10 limits the notification of forgetting to remove the ETC card by turning off the card removal forgetting notification setting. The restriction process (S19) is a process for realizing the restriction unit 107. As a result, the forgetting to remove warning sound is not output when the idling state is changed. In addition to or instead of turning off the card removal forget notification setting, the control unit 10 may interrupt the enable signal output to the audio output unit 7.

  In the maintenance process (S20-S23), the control unit 10 maintains the power supply to the functional unit selected in the selection process (S15-S17). On the other hand, since the power supply is not maintained in the function unit that has not been selected, the execution of the function is stopped. The maintenance process (S20-S23) is a process for realizing the power supply selection unit 102.

  When the GPS positioning state is not established and the communication link is not established (S15: NO, S16: NO), the control unit 10 drives only the switching unit 25 (see FIGS. 2 and 3) provided in the control unit 10. Thus, only the control unit 10 is connected to the auxiliary power source 300 to maintain power supply (S20).

  When the communication link is being established without being in the GPS positioning state (S15: NO, S16: YES), the control unit 10 drives the control unit 10 and the switching unit 25 provided in the wireless communication unit 4, respectively. Thus, the control unit 10 and the wireless communication unit 4 are connected to the auxiliary power source 300 to maintain power supply (S21).

  When in the GPS positioning state and the communication link is not established (S15: YES, S17: NO), the control unit 10 drives the switching unit 25 provided in the control unit 10 and the GNSS reception unit 5 respectively. Then, the controller 10 and the GNSS receiver 5 are connected to the auxiliary power supply 300 to maintain power supply (S22).

  When the GPS positioning state is established and the communication link is being established (S15: YES, S17: YES), the control unit 10 switches the control unit 10, the wireless communication unit 4, and the switching unit 25 provided in the GNSS receiving unit 5. Are respectively connected to the control unit 10, the wireless communication unit 4, and the GNSS receiving unit 5 to the auxiliary power source 300 to maintain power supply (S23).

  Thereafter, when the input voltage exceeds the second threshold (S24), the control unit 10 restarts the stopped function unit and stops driving the switching unit 25 (S25), and returns to normal operation (S26). .

  Further, when the accessory power source is turned off (S27), the control unit 10 ends the process after notifying that the user has forgotten to remove the ETC card (S28: YES) (S29). If no ETC card is inserted (S28: NO), the process is terminated.

  By maintaining the power supply to the control unit 10 as in S20 to S23, the function of the control unit 10 (in particular, as the authentication unit 109 in this case) as shown in FIG. Since the execution of the function) is maintained, the ETC card remains authenticated, and the authentication process is not performed again even when the input voltage is restored. For this reason, it is possible to prevent the card authentication completion notification from being performed every time the state changes to the idling state.

  Further, since the setting for forgetting to remove the card is turned off when the input voltage is lowered, it is possible to prevent the notification of forgetting to remove the card every time the state changes to the idling state.

  By maintaining the power supply of the wireless communication unit 4 in addition to the control unit 10 as in the above S21 and S23, as shown in FIG. 6, even if the input voltage decreases during establishment of the communication link, the wireless communication unit 4 Since the execution of this function is maintained, it is possible to continue communication with the roadside machine. In other words, even if it changes to an idling state while establishing a communication link with a roadside device due to traffic jams on a highway or waiting for a signal on a general road, communication with the roadside device is continued and communication errors are suppressed. It is possible.

  By maintaining the power supply of the GNSS receiver 5 in addition to the controller 10 as in S22 and S23, the function of the GNSS receiver 5 can be achieved even when the input voltage is lowered in the positioning state as shown in FIG. Since the execution of is maintained, it is possible to shift to a backup state that retains information at the time of positioning. For this reason, compared with the case where the GNSS receiver 5 shifts from the stop state to the positioning state (so-called cold start), it is possible to shorten the time until the transition to the positioning state again.

DESCRIPTION OF SYMBOLS 1 Onboard equipment, 10 Control part, 12 Memory | storage part, 14 Function part monitoring part, 2 Power supply circuit, 20 Power supply part, 21 Power supply connector, 23 Voltage adjustment part, 25 Switching part, 26 Voltage detection part, 27 Internal voltage detection part, 28 external voltage detection unit, 29 logic operation unit, 3 device communication unit, 32 I / F connector, 4 wireless communication unit, 43 antenna connector, 45 antenna, 5 GNSS reception unit, 6 light emitting unit, 7 audio output unit, 8 operation Input unit, 9 card holder, 92 card detection unit, 94 forgetting to remove notification unit, 102 power supply selection unit, 107 restriction unit, 109 authentication unit, 200 function unit, 300 auxiliary power supply, 400 battery

Claims (16)

A plurality of functional units for executing different on-board device functions;
A power supply unit that supplies power received from a battery of the vehicle to the plurality of functional units;
A voltage detector that outputs a voltage drop detection signal indicating a drop in the voltage of the power;
When a function unit that maintains execution of the on-vehicle device function is selected from the plurality of function units, and the voltage drop detection signal is output from the voltage detection unit, power supply to the selected function unit A power supply selection unit for maintaining
On-vehicle device equipped with. A function unit monitoring unit that monitors a state of the plurality of function units and outputs a determination signal indicating whether or not the onboard function is executed in each function unit;
The voltage supply selection unit selects a function unit in an execution state from the plurality of function units based on the determination signal.
The vehicle-mounted device according to claim 1. The power supply selection unit selects a function unit having a priority order of a predetermined value or more from the plurality of function units based on a priority order of execution of the in-vehicle device function in each function unit stored in advance.
The vehicle-mounted device according to claim 1. The power supply selection unit selects a functional unit having a power consumption of a predetermined value or less from the plurality of functional units based on power consumption under execution of the vehicle-mounted device function in each functional unit stored in advance. ,
The vehicle-mounted device according to claim 1. Provided in each of the plurality of functional units, further comprising a plurality of switching units for switching between connection and disconnection of the auxiliary power supply,
The power supply selection unit maintains power supply to the selected functional unit by driving a switching unit corresponding to the selected functional unit among the plurality of switching units.
The vehicle-mounted device according to any one of claims 1 to 4. The power supply unit steps down the voltage of the vehicle battery and supplies the voltage to the plurality of functional units.
The upstream of the power supply unit is used as the auxiliary power supply,
The in-vehicle device according to claim 5. The switching unit includes a booster.
The vehicle-mounted device according to claim 5 or 6. The voltage detector detects a voltage upstream of the power supply;
The vehicle-mounted device according to any one of claims 1 to 7. The voltage detection unit detects an upstream voltage and a downstream voltage of the power supply unit,
The vehicle-mounted device according to any one of claims 1 to 7. When the voltage drop detection signal is output, further comprising a restriction unit that restricts execution of a specific function,
The vehicle-mounted device according to any one of claims 1 to 9. The restriction unit restricts notification of forgetting to remove the ETC card when the voltage drop detection signal is output.
The vehicle-mounted device according to claim 10. The power supply selection unit also maintains power supply to itself when the voltage drop detection signal is output.
The vehicle-mounted device according to any one of claims 1 to 11. An authentication unit for executing an ETC card authentication process;
One of the plurality of switching units is provided in the authentication unit,
The power supply selection unit maintains a power supply to the authentication unit by driving a switching unit corresponding to the authentication unit.
The in-vehicle device according to claim 5. The power supply connection to the power supply circuit is a two-wire system in which two wires of an accessory power supply line and a ground line are connected
The vehicle-mounted device according to any one of claims 1 to 13. A plurality of functional units for executing different on-board device functions;
A power supply unit that supplies power received from a battery of the vehicle to the plurality of functional units;
A method for controlling an in-vehicle device comprising:
Output a voltage drop detection signal indicating a drop in the voltage of the power,
Select a functional unit that maintains the execution of the vehicle-mounted device function from the plurality of functional units, and when the voltage drop detection signal is output, maintain power supply to the selected functional unit.
Control method for in-vehicle equipment. A plurality of functional units for executing different on-board device functions;
A power supply unit that supplies power received from a battery of the vehicle to the plurality of functional units;
A voltage detector that outputs a voltage drop detection signal indicating a drop in the voltage of the power;
On-board computer equipped with
When a function unit that maintains execution of the on-vehicle device function is selected from the plurality of function units, and the voltage drop detection signal output from the voltage detection unit is output, to the selected function unit A power supply selection unit that maintains the power supply of
Program to function as.

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