JP2019064531A - Startup detection device and power supply control device - Google Patents

Abstract

To provide a startup detection device capable of further enhancing detection accuracy of engine start with a simple circuit configuration.SOLUTION: There is provided a startup detection device comprising a digital type vibration sensor 11 and a control part 12. The startup detection device transmits a wake-up signal to the control part 12 when there is possibility in which, the engine startup is performed by the vibration sensor 11, and makes a state of the control part 12 a wake-up state. Therefore, when the wake-up signal is not transmitted from the vibration sensor 11, the control part 12 turns into a sleep state, and the control part 12 can be actuated by an extremely low current consumption. In addition, after the wake-up, it is possible to determine whether or not the engine startup is performed on the control part 12 on the basis of a detection signal according to vibration transmitted from the vibration sensor 11. Therefore, it is possible to determine properly, whether or not vibration detected by the vibration sensor 11 is caused by engine startup.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a start detection device for detecting an engine start in a vehicle and a power supply control device for controlling power supply from a power source based on the engine start, and in particular, applied to in-vehicle devices attached to a vehicle It is suitable.

  The power supply signal in the vehicle includes a + B signal, which is a constant power supply signal that is constantly supplied, and an ignition (hereinafter referred to as IG) signal, which is supplied when the engine is operated. Is performed based on the IG signal. For example, when a battery and an in-vehicle device are connected through a connector and an IG switch provided between the battery and the in-vehicle device is turned on at engine start, a battery voltage is transmitted as an IG signal through the connector. Input to in-vehicle device. The on-vehicle device is driven based on the input of the IG signal.

  However, in some in-vehicle devices, the IG signal is not directly input, and only the + B signal is input. For example, in-vehicle devices to be retrofitted to a vehicle are often configured not to receive an IG signal directly. Such vehicle-mounted devices can not detect engine start based on the IG signal. Therefore, wiring is added to a cigarette lighter socket or the like to which the IG signal is input, and the wiring is drawn around and connected to the in-vehicle device so that the IG signal is input to the in-vehicle device. However, additional wiring is required, resulting in an increase in the number of parts and a deterioration in appearance, which also increases the number of steps for mounting the on-vehicle device.

  Therefore, Patent Document 1 proposes a start detection device capable of detecting whether or not an engine in a vehicle has started. This start detection device is configured to include a vibration sensor that detects vibration by the engine and a detection circuit that detects start of the engine based on a detection signal of the vibration sensor, and stops the drive of the cell motor when the engine start is detected. It is supposed to be. The detection circuit is configured by an analog circuit such as an amplifier or a low pass filter that amplifies a detection signal of the vibration sensor.

JP, 2005-146982, A

  However, when engine start detection is performed using an analog circuit as in the start detection device of Patent Document 1, the circuit configuration becomes complicated, and it is difficult to perform detection with higher accuracy.

  An object of the present invention is to provide a start detection device and a power control device capable of further enhancing the detection accuracy of the engine start with a simple circuit configuration.

  In order to achieve the above object, the invention according to claim 1 is a start detection device which is applied to a vehicle and detects that an engine start has been performed, and outputs a detection signal according to the vibration of the vehicle. The vibration sensor (11) detects vibrations that may have caused engine start based on the detection signal and outputs a wakeup signal, and sleeps before the wakeup signal is transmitted from the vibration sensor And a control unit (12) for determining whether or not the engine start has been performed based on the detection signal.

  As described above, when there is a possibility that the engine start has been performed by the vibration sensor, a wakeup signal is transmitted to the control unit to bring the control unit into the wakeup state. As a result, when the wakeup signal is not transmitted from the vibration sensor, the control unit is put into the sleep state, and the control unit can be operated with an extremely low current consumption. In addition, after the wake-up, it is possible to determine whether the engine start has been performed based on the detection signal according to the vibration transmitted from the vibration sensor by the control unit. Therefore, in the control unit, it is possible to accurately determine whether the vibration detected by the vibration sensor is due to engine start or another factor such as vibration due to opening and closing of a door. As a result, it is possible to make the start detection device capable of further enhancing the detection accuracy of the engine start with a simple circuit configuration.

  For example, as described in claim 2, the control unit determines whether or not periodic vibration is occurring based on the detection signal, and if periodic vibration is occurring, the engine start is performed. It can be determined.

  In the invention according to claim 3, the control unit detects the vibration at the opening and closing of the door based on the detection signal, and whether or not the engine start is performed after the vibration at the opening and closing of the door is detected Determine

  Before the start of the engine, the door is opened and closed. Therefore, when vibration at the time of opening and closing the door is detected, if vibration generated at the time of starting the engine is detected, it is determined that the engine is started and if vibration at the opening and closing of the door is not detected, engine starting Even if vibrations that sometimes occur are detected, it may not be determined that the engine has been started.

  In the invention according to claim 4, the start detection device according to any one of claims 1 to 3 and, under the control of the control unit, it is turned on when it is determined that the engine start has been performed, and the engine start And the power switch (13) is turned off when it is determined that the operation is not performed, and the power switch is turned on to supply power to the functional unit (14), and the power switch is turned off Stop the power supply to the function unit.

  Thus, the engine start is detected using the start detection device according to any one of claims 1 to 3, and power supply to the functional unit is performed when the engine start is detected. Can.

  In addition, the code | symbol in the parenthesis of each said means shows an example of the correspondence with the specific means as described in embodiment mentioned later.

It is the circuit diagram which showed the circuit structure of the vehicle-mounted apparatus to which the power supply control apparatus provided with the starting detection apparatus concerning 1st Embodiment was applied, and the power supply form from a battery. It is the wave form diagram which showed the appearance of the detection signal and the wakeup signal of a vibration sensor. It is the flowchart which showed the detail of the power supply control processing which CPU of a control part performs.

  Hereinafter, an embodiment of the present invention will be described based on the drawings. In the following embodiments, parts that are the same as or equivalent to each other will be described with the same reference numerals.

First Embodiment
A power supply control device provided with the start detection device according to the first embodiment will be described. Although the case where the power supply control device provided with the start detection device is applied to an in-vehicle device to be retrofitted to a vehicle is described as an example, the present invention is not limited to the retrofit in-vehicle device. May be applied to in-vehicle devices. Examples of such on-vehicle devices include on-vehicle devices that can be operated during engine operation but can not be operated during engine operation, such as drive recorders and air purifiers.

  As shown in FIG. 1, the vehicle is provided with a battery 1 serving as a power source, and an IG terminal 2 and a + B terminal 3 are connected to the battery 1.

  The IG terminal 2 is connected to the battery via an IG switch 4 which is turned on by engine start and turned off when the engine is stopped. With respect to various in-vehicle devices (not shown) connected to the IG terminal 2, for example, a cigarette lighter socket, a battery voltage is applied as an IG signal when the IG switch 4 is turned on.

  The + B terminal 3 is connected to the battery 1 and is always energized regardless of whether the engine is operating or not, and applies a power supply voltage to the on-vehicle device 10 as a + B signal. Here, although a mode in which + B terminal 3 is directly connected to battery 1 is shown, a power supply circuit (not shown) generates a constant power supply voltage based on battery 1 and uses this as a + B signal. Also good. A retrofit vehicle device 10 is connected to the + B terminal 3.

  The on-vehicle device 10 is, for example, a device such as a drive recorder or an air purifier, which is not required to be activated when the engine is not in operation, but is desired to be activated while the engine is in operation. The in-vehicle device 10 may be attached to any position of the vehicle. In the case of the present embodiment, the on-vehicle device 10 is provided with a power control device including a start detection device.

  Specifically, the on-vehicle device 10 includes a vibration sensor 11, a control unit 12, a power switch 13, and a peripheral circuit 14.

  The vibration sensor 11 is a digital sensor that outputs a detection signal according to the vibration, and is configured of, for example, an acceleration sensor or the like. Specifically, in addition to being able to output the raw data of the detection signal according to the vibration, the vibration sensor 11 detects the vibration that may have caused the engine start based on the output waveform of the detection signal, A detection signal indicating that is transmitted to the control unit 12 as a wakeup signal.

  Specifically, the vibration sensor 11 outputs a voltage signal as a detection signal corresponding to the vibration. This voltage signal is outputted as a signal that vibrates according to the periodic vibration as shown in FIG. 2 because the periodic vibration corresponding to the engine speed occurs when the engine is started. The voltage signal at this time has a large voltage value as compared with the case where the engine is not in operation and no other vibration occurs. Therefore, when the engine is not in operation and the output waveform of the voltage signal according to the vibration is compared with the voltage threshold and the voltage threshold is exceeded, a detection signal indicating that the engine start may have been performed. Is output as a wakeup signal. The voltage threshold is set to a value larger than the value of the voltage signal that can be output when the engine is not in operation and no other vibration occurs.

  Also, although the vibration sensor 11 transmits a detection signal corresponding to the vibration to the control unit 12, the transmission of this detection signal is a detection signal indicating that there is a possibility of engine start, that is, a wakeup signal. It may be done after output of.

  The control unit 12 is constituted by a known microcomputer or the like provided with a CPU, a ROM, a RAM, an I / O and the like, and executes a predetermined process according to a program of CPU control software stored in the ROM or the like. In the case of the present embodiment, the CPU of the control unit 12 is in the sleep state until the wakeup signal from the vibration sensor 11 is transmitted, and is operated with an extremely low current consumption. In this state, the CPU does not determine that the engine has been started or that the engine operation has been stopped even if a detection signal corresponding to the vibration is transmitted from the vibration sensor 11. Then, when the wakeup signal is input from the vibration sensor 11, the CPU is brought into a wakeup state, based on the detection signal according to the vibration transmitted from the vibration sensor 11, that the engine start is performed or the engine operation To determine that has been stopped.

  The control unit 12 also controls the power switch 13. Specifically, the control unit 12 turns on the power switch 13 when detecting that the engine start has been performed. Then, the control unit 12 keeps the power switch 13 turned on while the engine is in operation, and turns off the power switch 13 when detecting the stop of the engine operation.

  The power switch 13 is a switch that controls on / off of the connection between the + B terminal 3 and the peripheral circuit 14. When the power switch 13 is turned on, the + B terminal 3 and the peripheral circuit 14 are connected, and a power supply voltage is applied to the peripheral circuit 14 as a + B signal through the + B terminal 3. When the power switch 13 is turned off, the + B terminal 3 and the peripheral circuit 14 are disconnected, and the application of the power supply voltage to the peripheral circuit 14 is stopped.

  The peripheral circuit 14 is a circuit that constitutes a functional unit of the in-vehicle device 10. When the application of the power supply voltage to the peripheral circuit 14 is started, the peripheral circuit 14 is operated, and the function of the on-vehicle device 10 is realized. For example, when the in-vehicle device 10 is a drive recorder, the peripheral image is captured through a built-in camera, and the function of storing the image data is realized. When the on-vehicle device 10 is an air purifier, the built-in fan is driven to realize functions such as suction of air and discharge of air through a filter.

  As described above, the battery 1 and the IG terminal 2 and the + B terminal 3 in the vehicle are connected, and the on-vehicle device 10 connected to the + B terminal 3 is configured. A power supply control device including the vibration sensor 11 and the control unit 12 of the in-vehicle device 10 configured as described above and a start detection device including the vibration sensor 11, the control unit 12 and the power switch 13 Is configured.

  Next, the operation of the in-vehicle device 10 will be described based on the power control process executed by the CPU of the control unit 12 shown in FIG. 3. Note that the power control process shown in FIG. 3 is executed by the CPU at predetermined control cycles.

  First, the vibration sensor 11 operates based on the power supply voltage applied through the + B terminal 3 and outputs a detection signal according to the vibration transmitted from the vehicle as shown in FIG. By comparing with the voltage threshold, it is possible to detect the vibration that may have caused the engine start. Then, when the vibration sensor 11 detects a vibration that may have caused the engine start, as in the case where the output waveform of the detection signal exceeds the voltage threshold, the detection signal is used as a wakeup signal to the control unit 12 It is supposed to communicate.

  On the other hand, in the state before the engine start is detected, the CPU of the control unit 12 goes to sleep as shown in step S100. Then, in step S110, it is determined whether or not a wakeup signal is transmitted from the vibration sensor 11, and if transmitted, the process proceeds to step S120 and subsequent steps, and if not transmitted, the process returns to step S100 and continues the sleep state.

  Subsequently, when a wakeup signal is transmitted from the vibration sensor 11, the process proceeds to step S120 to switch to the wakeup state. Then, in step S130, a detection signal corresponding to the vibration transmitted from the vibration sensor 11 is input, and then in step S140, it is determined based on the detection signal input in step S130 whether or not engine start has been performed. For example, as described above, since the periodic vibration corresponding to the engine speed occurs during engine operation, the CPU starts the engine by determining whether or not the periodic vibration is generated. It can be determined whether it is vibration.

  Here, if it is determined in step S140 that the engine start has been performed, the process proceeds to step S150 and the power switch 13 is turned on. As a result, application of the power supply voltage to the peripheral circuit 14 is started, and the peripheral circuit 14 is operated to realize the function of the on-vehicle device 10.

  After the power switch 13 is turned on in step S150, the determination process of step S140 is repeatedly executed. Therefore, in step S140, the power switch 13 is maintained on continuously during the period when it is determined that the engine has been started, that is, if the engine is in operation if the engine has been started. It will be

  On the other hand, when it is determined in step S140 that the engine start is not performed, the process proceeds to step S160. Then, in step S160, based on the detection signal input in step S130, it is determined whether or not a state in which there is no vibration continues for a certain period. When the engine is not started or when the engine is not in operation after the start, the vibration based on the engine operation is not generated, and the vibration does not continue for a certain period. Therefore, if it is determined in step S160 that no vibration continues for a certain period, the process proceeds to step S170, and the power switch 13 is turned off. In this case, the process returns to step S100 to switch to the sleep state, and the sleep state is maintained until the wakeup signal is input next.

  Thus, the power control process by the control unit 12 of the power control apparatus according to the present embodiment is executed.

  As described above, the power supply control device according to the present embodiment includes the start detection device having the digital vibration sensor 11 and the control unit 12. Then, in the start detection device, when there is a possibility that the engine start has been performed by the vibration sensor 11, a wakeup signal is transmitted to the control unit 12 to bring the control unit 12 into a wakeup state. As a result, when the wakeup signal is not transmitted from the vibration sensor 11, the control unit 12 is put into the sleep state, and the control unit 12 can be operated with a very low current consumption.

  In addition, after the wakeup, it is possible to determine whether or not the engine start has been performed based on the detection signal according to the vibration transmitted from the vibration sensor 11 by the control unit 12. Therefore, the control unit 12 can accurately determine whether the vibration detected by the vibration sensor 11 is due to engine start or another factor such as vibration due to the opening and closing of the door.

  Therefore, even in the on-vehicle apparatus 10 to which the IG signal is not directly input, it is possible to accurately determine that the engine start has been performed without adding a wiring for inputting the IG signal. Further, since it is possible to determine that the engine has been started by the start detection device configured by the digital vibration sensor 11 and the control unit 12, a complicated circuit configuration as in the case of using an analog circuit is not required, And, it becomes possible to perform more accurate detection. Furthermore, since all such control can be realized as digital control, the configuration of the on-vehicle apparatus 10 can be simplified.

  Further, in the power supply control device, when it is determined in the control unit 12 that the engine start has been performed, the power supply switch 13 is turned on to supply power to the peripheral circuit 14. Therefore, the power supply to the peripheral circuit 14 can be limited only when the engine start is performed, and the power supply is performed only when it is really necessary, so that the consumption of the in-vehicle device 10 can be achieved. It is possible to reduce power consumption.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and appropriate modifications can be made within the scope of the claims.

  For example, as described above, although the control unit 12 detects that the engine start has been performed based on the detection signal of the vibration sensor 11, more accuracy can be obtained by performing another determination in the control unit 12 as well. The engine start can be detected well. That is, in addition to the vibration generated when the engine is started, the vehicle may generate a vibration. For this reason, by determining also for vibrations other than engine start, it is possible to further improve the detection accuracy of engine start. For example, vibration also occurs in the vehicle when the door is opened and closed. However, since the vibration generated when the door is opened and closed is instantaneous, it does not become a periodic vibration, and the vibration ends in a short period. For this reason, when the control unit 12 detects that the vibration is a non-periodic momentary vibration based on a detection signal of the vibration sensor 11 and a magnitude of vibration generated when the door is opened and closed, It can be determined that the vibration at the time of opening and closing is determined, that is, the vibration other than the engine start.

  On the other hand, when the engine start is performed, the opening and closing operation of the door is performed before that. Therefore, when vibration at the time of opening and closing the door is detected, if vibration generated at the time of starting the engine is detected, it is determined that the engine is started and if vibration at the opening and closing of the door is not detected, engine starting Even if vibrations that sometimes occur are detected, it may not be determined that the engine has been started.

DESCRIPTION OF SYMBOLS 1 battery 2 IG terminal 3 + B terminal 4 power switch 10 vehicle-mounted apparatus 11 vibration sensor 12 control part 13 power switch 14 peripheral circuit

Claims (4)

A start detection device applied to a vehicle and detecting that an engine start has been performed,
A vibration sensor (11) that outputs a detection signal according to the vibration of the vehicle and detects a vibration that may have caused the engine start based on the detection signal, and outputs a wakeup signal;
Before the wakeup signal is transmitted from the vibration sensor, the sleep state is entered, and when the wakeup signal is transmitted, the wakeup state is entered, and it is determined whether the engine start has been performed based on the detection signal. And a control unit (12).   The said control part determines whether periodic vibration has arisen based on the said detection signal, and if periodic vibration has arisen, it will determine that the said engine start was performed. Start detection device.   The control unit detects vibration at the time of opening and closing of the door based on the detection signal, and determines whether or not the engine start is performed after the vibration at the time of opening and closing of the door is detected. The start detection device according to or 2. A start detection device according to any one of claims 1 to 3;
And a power switch (13) controlled by the control unit and turned on when it is determined that the engine start has been performed, and turned off when it is determined that the engine start has not been performed,
A power supply control device that supplies power to a functional unit (14) by turning on the power switch, and stops power supply to the functional unit by turning off the power switch.

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