Power supply control device

Abstract

To provide a power supply control device that can supply electric power to car accessories for various kinds of vehicles during a battery traveling and idling stop.SOLUTION: A device includes: a communication unit 34 for communicating with a vehicle-side computer 5 via an in-vehicle communication network 7; a noise detection unit 33 for detecting noise generated from power supply voltage upon starting of a vehicle; a relay switch 36 for turning the power supply voltage on / off which is supplied from a power supply to a car accessory 20; and a control unit 35 for using a signal from the vehicle-side computer 5 received by the communication unit 34 and the noise detected by the noise detection unit 33 to control on / off of the relay switch 36.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power supply control device for car accessories, such as aftermarket car accessories, that are added by users to the interior of a vehicle after it has left the factory, and in particular to a power supply control device that supplies power to car accessories only when the vehicle is running or in a running preparation state. [Background technology]

[0002] Generally, a power connection socket (cigarette lighter socket or accessory socket: hereafter referred to as accessory socket) is provided near the driver's seat or rear seat of a car to supply power from the car's battery to aftermarket car accessories such as map lamps used inside the car. Depending on the make and model of the car, accessory sockets can be either ones that turn on the power supply when the car's key (ignition switch) is in the ACC (accessory) position, or ones that maintain the power supply on regardless of the ignition switch position.

[0003] For example, if a car accessory that uses power continuously is installed in a car that has an accessory socket that keeps the power supply ON (power supplied from the accessory socket), the battery may run out if the car is parked for a long period of time. To prevent such battery drain caused by car accessories, a power supply control device is known that does not supply power from the accessory socket to the car accessory when the power generator (alternator) linked to the engine is not operating (see, for example, Patent Document 1). In Patent Document 1, the operating state of the power generator (or engine) is detected by the power generator alternator noise superimposed on the battery output voltage.

[0004] In recent years, several manufacturers have released hybrid cars (HVs) equipped with both a traction motor and an engine, and some of these can travel a certain distance using only the battery without starting the engine. Also on the market are cars equipped with an idling stop function that temporarily stops the engine when waiting at a traffic light at an intersection, and quickly starts the engine when the light turns green and the accelerator is pressed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-222084 Summary of the Invention [Problem to be solved by the invention]

[0006] A standard automobile generally has one accessory socket, and even luxury cars or large vehicles with many passengers have two to three accessory sockets. However, one accessory socket is generally required for each car accessory, and if a passenger wants to use multiple car accessories at the same time, the number of accessory sockets may be insufficient.

[0007] Furthermore, in the case of automobiles that can run on battery power alone or automobiles with an idling stop function, the generator does not operate when the automobile is running on battery power or during idling stop, so alternator noise does not occur. In such automobiles, if the power supply control device of Patent Document 1 controls the power supply of car accessories, the car accessories cannot be used while the automobile is running on battery power or while the engine is stopped due to the idling stop function.

[0008] Therefore, in order to solve the above problems, the present invention aims to provide a power supply control device that can supply power from sources other than the accessory socket and can supply power to a wide variety of car accessories of a vehicle even when the vehicle is running on battery power or during idling stop. [Means for solving the problem]

[0009] (1) In order to solve the above problem, the power supply control device includes a communication means for communicating with a vehicle-side computer via an in-vehicle communication network, a noise detection means for detecting noise from the power supply voltage, a switch for turning on / off the power supply voltage supplied from the power supply to a specified electronic circuit, and a control means for controlling the on / off of the switch using a signal from the vehicle-side computer received by the communication means and the noise detected by the noise detection means.

[0010] The power supply control device uses a signal output from the vehicle computer to the in-vehicle communication network to control the ON / OFF of the power supply voltage supplied to a specified electronic circuit, which reduces erroneous judgments compared to when noise alone is the cause, and when noise cannot be detected, it can supply power to a specified electronic circuit using the signal received from the vehicle computer. The predetermined electronic circuit may be, for example, an electronic circuit provided inside a car accessory, etc. Furthermore, it is particularly preferable that the power supply control device is built into, for example, a connector of a power supply. Alternatively, a predetermined electronic circuit and the power supply control device may be incorporated into a car accessory or the like.

[0011] (2) Preferably, the noise detection means of the power supply control device detects noise generated when the vehicle is started.

[0012] For example, in a vehicle equipped with an internal combustion engine, noise generated during vehicle startup due to a voltage drop caused by an engine starter may be used instead of conventional alternator noise from a power generator. Alternator noise is noise resulting from the operation of an AC power generator that remains even after rectification, resulting in a relatively low noise level at a relatively high frequency. In contrast, noise generated during vehicle startup is noise generated by the starter, which uses such a large amount of power that a voltage drop occurs even when all other electrical components are shut off. This reduces noise detection errors. Furthermore, in an electric vehicle or hybrid vehicle, noise generated during vehicle startup may include noise generated when power supply to various vehicle components is initiated. For example, in an electric vehicle or hybrid vehicle, power supply is initiated upon establishment of communication with a transmitter owned by the driver, determining whether noise of the same pattern as the noise generated at that time is generated. This noise may be noise due to a voltage drop. By using noise generated during vehicle startup, which has fewer detection errors, and a signal received from a vehicle-mounted computer, power can be reliably supplied to specified electronic circuits after the vehicle has started.

[0013] (3) Preferably, the control means of the power supply control device does not turn off the switch when it can receive a signal from the vehicle computer, even if the noise detection means does not detect noise generated when the vehicle is started.

[0014] In this way, the power supply control device can supply power to specified electronic circuits even when the vehicle is running on battery power or during idling stop. This is because in hybrid cars (HVs) and automobiles with idling stop functions, the vehicle's computer is awake and outputs speed information and driving-related information even when the vehicle is running on battery power or during idling stop.

[0015] (4) Preferably, in the power supply control device, the noise generated when the vehicle is started is noise that includes a voltage drop that occurs when the engine of a vehicle having an engine is started. In this way, the noise detection means can accurately detect the start of a vehicle having an engine.

[0016] (5) Preferably, the noise detection means of the power supply control device detects noise generated when the vehicle is started as noise that includes a voltage drop that occurs when the power supply to the electric vehicle is turned on. In this way, the noise detection means can accurately detect the start of the electric vehicle.

[0017] (6) Preferably, the control means of the power supply control device is configured to turn on the switch when the noise detection means detects noise generated when the vehicle is started after the communication means has received a signal from the vehicle-side computer.

[0018] In this way, in the power supply control device, by turning on the switch when noise is detected after the communication means receives a signal from the vehicle-side computer, erroneous determination can be reliably prevented. For example, the vehicle-side computer of a vehicle having a security function such as an immobilizer transmits a signal to disable the security function before the vehicle starts, which generates vehicle noise. Therefore, by turning on the switch when noise is detected after receiving this signal, erroneous determination can be reliably prevented for vehicles having security functions. "After being able to receive a signal from the vehicle-side computer" preferably refers to after a state in which signals from the vehicle-side computer cannot be received changes to a state in which signals from the vehicle-side computer can be received. It is particularly preferable that the signal received from the vehicle-side computer is a signal that is not output when the vehicle is in a state in which it cannot start moving.

[0019] (7) Preferably, the communication means of the power supply control device uses both an in-vehicle communication network that outputs a spontaneous output signal from the vehicle-side computer and an in-vehicle communication network that outputs a response output signal from the vehicle-side computer.

[0020] In this way, the power supply control device can accurately control the supply of power to a specified electronic circuit with just one power supply control device, regardless of whether the network being used is an in-vehicle communication network that uses a spontaneous output signal or a response output signal. Note that a spontaneous output signal is a signal that is actively output from the vehicle-side computer, and a response output signal is a signal that is passively output from the vehicle-side computer only when a response request is received.

[0021] (8) Preferably, the communication means of the power supply control device is configured to be able to connect to and communicate with a plurality of different in-vehicle communication networks, and the control means monitors the plurality of different in-vehicle communication networks connected to the communication means, and determines whether the switch is on or off using information from the in-vehicle communication networks with which the communication means of the plurality of different in-vehicle communication networks can communicate.

[0022] In this way, the power supply control device uses an in-vehicle communication network that can communicate among multiple different in-vehicle communication networks, so that for vehicle models with a wide variety of in-vehicle communication networks, only one power supply control device can supply power to a specified electronic circuit.

[0023] (9) Preferably, the control means of the power supply control device turns on the switch when it receives a signal from the vehicle-side computer, and turns off the switch when it is no longer possible to receive a signal from the vehicle-side computer.

[0024] In this way, the control means of the power supply control device turns on the power supply voltage supplied to the specified electronic circuit when it receives a signal from the vehicle computer, not when it detects noise from the power supply voltage, and turns off the power supply voltage supplied to the specified electronic circuit when it can no longer receive a signal from the vehicle computer.In other words, by turning on the power supply voltage supplied to the specified electronic circuit when the vehicle computer is awake, it is possible to use the specified electronic circuit while driving, even in hybrid cars (HVs) or cars with an idling stop function.

[0025] (10) Preferably, the power supply control device is provided with a connection means for connecting to an in-vehicle connector for self-diagnosis including a connection terminal for an in-vehicle communication network and a power supply terminal.

[0026] For example, it is preferable to provide a connection means (for example, a connector corresponding to the in-vehicle connector of the OBD, etc.) that can be connected to an in-vehicle connector such as an OBD that is exposed inside the vehicle. The in-vehicle connector of the OBD is provided with a terminal for supplying power in addition to a terminal for connecting to the in-vehicle communication network, so even if the user does not have knowledge of in-vehicle wiring, the user can connect and disconnect the power supply by themselves, and installation can be performed without having to go to a repair shop, etc.

[0027] Depending on the type of in-vehicle communication network used by the automobile, the signals output from the vehicle-side computer to the in-vehicle communication network include spontaneous output signals (spontaneous output signals: for example, signals for CAN (Controller Area Network)) that are output after the vehicle-side computer is started up, even if no response request signal is received from elsewhere, and responsive output signals (response output signals: for example, signals for K-Line) that are output only when a response request signal is received from elsewhere.

[0028] Some vehicle computers are equipped with a self-diagnosis (on-board diagnosis: OBD) I or II system (software), which is required due to exhaust gas regulations and other factors. For example, when diagnosing a car's engine, a data-reading scan tool is connected to the OBD connector exposed inside the vehicle, and the scan tool reads the signals output from the vehicle computer to the in-vehicle communication network to diagnose the fault. In this case, if the in-vehicle communication network connected to the vehicle computer is the CAN mentioned above, the signal will be output spontaneously, so it is only necessary to wait for the signal and analyze whether it was output from the vehicle computer. However, if the in-vehicle communication network is the K-Line mentioned above, signals cannot be received by simply waiting, so a response request signal must first be sent and then the response signal output from the vehicle computer must be waited for.

[0029] General-purpose car accessories can be installed in a wide variety of automobiles. Current domestic automobiles use a variety of networks, including the CAN and K-Line, as well as proprietary in-vehicle communication networks, in-vehicle multimedia networks, door and seat networks, and security networks. However, self-diagnosis systems use either the CAN or K-Line signals output from the vehicle computer and use an OBD in-vehicle connector (the connector shown in Figure 3, described below) as the connector. Therefore, the vehicle computer can be determined to be awake by receiving a CAN signal from the OBD in-vehicle connector and interpreting it as a signal from the vehicle computer, or by sending a K-Line response request signal to the OBD in-vehicle connector and receiving a response output signal. By connecting the power supply control device to the in-vehicle connector for self-diagnosis using the connection means, power can be supplied from sources other than the accessory socket, making it possible to provide a power supply control device that can be installed in a wide variety of vehicle models.

[0030] (11) Preferably, the power supply control device has a housing having a connection means, and the housing contains a communication means, a noise detection means, and a control means. In this way, the power supply control device has the communication means, noise detection means, and control means inside a housing having the connection means, so there is no need to provide noise detection means and control means in the predetermined electronic circuit that receives power from this power supply control device, making it possible to miniaturize, for example, car accessories, etc. Furthermore, it is possible to eliminate malfunctions that may occur when noise detection means is provided in car accessories, etc., due to external noise being mixed into the power supply line between the car accessories, etc.

[0031] (12) Preferably, the control means of the power supply control device detects a spontaneous output signal from the vehicle-side computer via the in-vehicle communication network using the communication means, detects noise generated when the vehicle is started from the voltage of the power supply terminal using the noise detection means, sends a response request signal to the vehicle-side computer via the in-vehicle communication network using the communication means, detects a response output signal in response to the response request signal from the vehicle-side computer via the in-vehicle communication network using the communication means, and starts supplying power supply voltage to a specified electronic circuit when the spontaneous output signal or the response output signal is detected from the in-vehicle communication network.

[0032] For example, the control means of the power supply control device first receives a spontaneous output signal when the self-diagnosis signal from the vehicle-side computer is a CAN signal via the communication means, and if the spontaneous output signal cannot be received, detects noise generated when the vehicle is started using the noise detection means, and if noise generated when the vehicle is started is detected, sends a K-Line response request signal to the vehicle-side computer via the communication means and detects the K-Line response output signal. By detecting the wake-up of the vehicle-side computer in this way, it is possible to prevent unnecessary power consumption by sending a K-Line response request signal when the vehicle-side computer is not operating.

[0033] (13) Preferably, the control means of the power supply control device terminates the supply of power supply voltage to a specified electronic circuit when the communication means is no longer able to detect a spontaneous output signal or a response output signal from the in-vehicle communication network.

[0034] The control means of the power supply control device stops the supply of power supply voltage to a specified electronic circuit when the spontaneous output signal or response output signal can no longer be detected, thereby preventing unnecessary power consumption when the vehicle-side computer stops operating.

[0035] (14) Preferably, the control means of the power supply control device turns on the switch when the communication means detects a spontaneous output signal, and when the communication means sends a response request signal after the noise detection means detects noise and detects a response output signal in response to the response request signal. By doing this, the power supply control device can supply power to a specified electronic circuit with just one power supply control device, whether the vehicle's in-vehicle communication network is a type that outputs a spontaneous output signal from the vehicle's computer or a type that outputs a response output signal.

[0036] (15) Preferably, the control means of the power supply control device is triggered by the noise detection means detecting noise generated when the vehicle is started, to send a response request signal from the communication means. In this way, the power supply control device sends out a response request signal triggered by noise generated when the vehicle is started, so that if the in-vehicle communication network on the vehicle side is of a type that outputs a response output signal, the response request signal can be reliably sent from the communication means.

[0037] (16) Preferably, the control means of the power supply control device is provided with a timer means for measuring a predetermined time, and is configured to turn on the switch when a response output signal in response to the response request signal is detected from the communication means within the predetermined time after the response request signal is sent from the communication means. By doing this, the power supply control device turns on the switch if it detects a response output signal from the communication means in response to a response request signal within a specified time, so that power can be supplied to the specified electronic circuit even when noise cannot be detected by the noise detection means.

[0038] (17) Preferably, the control means of the power supply control device is provided with a timer means for measuring a predetermined time, and if the communication means can detect the next spontaneous output signal within the predetermined time after detecting the previous spontaneous output signal, the control means does not turn off the switch. By doing this, the power supply control device will not turn off the switch if it can continuously detect a spontaneous output signal from the communication means within a specified time, so that power supply to specified electronic circuits can continue even when the vehicle is running on battery or during idling stop.

[0039] (18) Preferably, the control means of the power supply control device is provided with a timer means for measuring a predetermined time, and if the noise detection means can detect the next noise within the predetermined time after detecting the previous noise, the control means does not turn off the switch. In this way, the power supply control device does not turn off the switch if the noise detection means detects continuous noise such as alternator noise, so that power can continue to be supplied to specified electronic circuits while the engine of a vehicle equipped with an engine is running. [Effects of the Invention]

[0040] As described above, the power supply control device of the present invention can supply power to specified electronic circuits such as car accessories from sources other than the accessory socket, and can supply power to specified electronic circuits such as car accessories of a wide variety of automobiles even when the automobile is running on battery power or during idling stop. [Brief explanation of the drawings]

[0041] [Figure 1] 1 is a block diagram showing an example of an in-vehicle communication network connected to a power supply control device of the present invention; [Figure 2] 1 is a block diagram showing a schematic configuration of an example of a power supply control device of the present invention; [Figure 3] 1 is a diagram showing the arrangement of terminal pins of an OBD connector. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0042] First Embodiment The vehicle 1 in FIG. 1 is driven by an engine 2. The rotating shaft of the engine 2 is connected to an alternator 3 by a belt or the like. The alternator 3 generates AC power by rotating an armature. The generated AC power is rectified to DC, and the DC output terminal is connected to the positive electrode of a battery 4. The positive electrode of the battery 4 is connected to a power output pin (for example, pin 16 in FIG. 3 , which will be described later) of an OBD in-car connector 6. A power supply control device 30 is connected to the OBD in-car connector 6, and a car accessory 20 is further connected to the power supply control device 30.

[0043] An engine sensor 12 and an engine sensor 13 are connected to the engine 2. The engine sensor 12 is a sensor that measures the rotation speed of the engine 2, and the engine sensor 13 is a sensor that measures the temperature of the engine 2. The tire 8 is the front tire, and the rotation sensor 10 is a sensor that detects the rotation of the tire 8. The tire 9 is the rear tire, and the rotation sensor 11 is a sensor that detects the rotation of the tire 9.

[0044] The in-vehicle communication network 7 is connected to the rotation sensors 10, 11, engine sensors 12, 13, and various other sensors (not shown), and is also connected to the vehicle-side computer 5. When the ignition key of the vehicle 1 is turned on, the rotation sensors 10, 11, engine sensors 12, 13, etc. and the vehicle-side computer 5 are energized and start operating. The in-vehicle communication network 7 transmits the detection results of the rotation sensors 10, 11, engine sensors 12, 13, etc. to the vehicle-side computer 5. The vehicle-side computer 5 determines the state of the engine and the state of the vehicle based on the detection results from the various sensors. The state of the vehicle includes whether the vehicle is running on battery power or is in an idling-stop state.

[0045] The in-vehicle communication network 7 includes the above-mentioned CAN and K-Line, as well as networks based on vehicle manufacturer's proprietary standards, such as LIN (Local Interconnect Network) and BEAN (Body Electronics Area Network), which are vehicle manufacturer's proprietary standards for body systems, FlexRay for high-speed control systems, and MOST (Media Oriented System Transport) for information systems.

[0046] If the in-vehicle communication network 7 is, for example, a CAN, the signal indicating the vehicle status described above is output spontaneously from the vehicle-side computer 5 even if no response request signal is received from another device. This signal is referred to as a spontaneous output signal in this specification. On the other hand, if the in-vehicle communication network 7 is, for example, a K-Line, the signal indicating the vehicle status described above is output as a response from the vehicle-side computer 5 only when a response request signal is received from another device. This signal is referred to as a response output signal in this specification. Whether the vehicle-side computer 5 outputs a spontaneous output signal or a response output signal depends on the connected network. Networks based on vehicle manufacturer-specific standards also output either a spontaneous output signal or a response output signal.

[0047] The power input connector 31 in Figure 2 is a connector on the power supply control device 30 side for connecting to the OBD in-vehicle connector. The power supply control device 30 receives power from the battery 4, which is the power source, via the power input connector 31, and transmits and receives signals to and from the vehicle-side computer 5. The power output connector 32 is a connector on the power supply control device 30 side for connecting to the power connector 21 of the car accessory 20. The power supply control device 30 supplies power to the car accessory 20 via the power output connector 32.

[0048] Inside the power supply control device 30, the power supply power supplied from the power supply is supplied to a noise detection unit 33 and a relay switch . A signal transmitted from the vehicle-side computer 5 is input to the communication unit 34 via the in-vehicle communication network 7. Conversely, the communication unit 34 communicates with the vehicle-side computer 5 via the in-vehicle communication network 7. Power supply power output from the relay switch 36 is supplied to the car accessory 20. The control unit 35 is connected to the noise detection unit 33, the communication unit 34, and the relay switch 36, and determines whether to turn the relay switch 36 ON or OFF based on the detection result of the noise detection unit 33, the communication result by the communication unit 34, and the time measurement result of the timer unit 37 in the control unit 35, and outputs either an ON or OFF signal. The relay switch 36 turns ON or OFF the power supply voltage supplied from the power source to the car accessory 20 in accordance with this signal.

[0049] The noise detection unit 33 has an AC component passing circuit 41, a filter 42, an amplifier circuit 43, a rectifier circuit 44, and a DC conversion circuit 45, and detects noise from the power supply voltage. The noise is, for example, noise that occurs when the vehicle 1 is started and is superimposed on the power supply voltage. In the case of a vehicle 1 having an engine 2, the noise that occurs when the vehicle 1 is started and detected by the noise detection unit 33 is noise that includes a voltage drop that occurs when the engine 2 is started. Note that if the vehicle 1 is a hybrid vehicle that is driven by a motor instead of the engine 2 and is running on battery power, or an electric vehicle, the noise that occurs when the vehicle 1 is started and detected by the noise detection unit 33 may be noise that includes a voltage drop that occurs when the power supply to the vehicle 1 is turned on.

[0050] The AC component passing circuit 41 removes DC voltage components from the output voltage of the battery 4 and passes only the AC component. The filter 42 extracts only signals in a target frequency band from the AC component output from the AC component passing circuit 41. The AC component passing circuit 41 is selected from a low-pass filter, a band-pass filter, and a high-pass filter depending on the target frequency to be detected. For example, alternator noise components that change in proportion to the engine speed are approximately 800 Hz to 8 kHz. Noise components generated when electrical components such as the air conditioner, headlights, and horn are turned on and off are in a higher frequency band than the alternator noise. Power supply voltage fluctuation components are in a low frequency band of several hundred Hz or less, and the voltage drop generated when the ignition key is turned on is in an even lower frequency band. Whether the vehicle 1 has an engine 2 or is an electric vehicle, noise including voltage drops is in a low frequency band and can be detected with a single filter. Below, we will explain the case where the frequency to be detected is the frequency of the voltage drop when the ignition key is turned on (when the vehicle 1 is driven by a motor rather than an engine 2 (when a hybrid vehicle is running on battery power or an electric vehicle), this is when the motor starts).

[0051] The signal in the target frequency band output from filter 42 is amplified by amplifier circuit 43, rectified by rectifier circuit 44, converted to a DC voltage by DC conversion circuit 45, and output as a control signal to control unit 35. By using a filter capable of detecting low-frequency noise including voltage drops in filter 42, noise detection unit 33 can accurately detect the start of vehicle 1 having engine 2, and can also accurately detect the start of electric vehicle 1. The control signal output from control unit 35 is either a high-level voltage signal or a low-level voltage signal with respect to a threshold value that turns relay switch 36 on and off. For example, when a high-level voltage signal is input, it means that the ignition key is turned on to start the engine (or the motor is started if vehicle 1 is driven by a motor rather than engine 2 (e.g., a hybrid vehicle running on battery power or an electric vehicle)). Therefore, control unit 35 outputs a signal to turn relay switch 36 on. On the other hand, when a low-level voltage signal is input, this means either that the ignition key is OFF (including when only the vehicle computer 5 is ON) or that it remains ON (including during idling stop) (when the vehicle 1 is driven by a motor rather than the engine 2 (when a hybrid vehicle is running on battery power or an electric vehicle), the motor is stopped), and the control unit 35 therefore makes the following judgment based on the input from the communication unit 34 and the measurement results of the timer unit 37.

[0052] When the control unit 35 is connected to the vehicle-side computer 5 via the in-vehicle communication network 7, it checks in advance whether the in-vehicle communication network 7 is a network that outputs a spontaneous output signal from the vehicle-side computer 5, or a network that outputs a response output signal in response to a response request signal, and if the in-vehicle communication network 7 needs to output a response request signal, for example, via K-Line, it outputs a response request signal from the communication unit 34 to the in-vehicle communication network 7 at predetermined time intervals measured by the timer unit 37. The predetermined time is determined by the standards / regulations for each type of in-vehicle communication network 7.

[0053] Furthermore, the control unit 35 determines whether the vehicle 1 is in a driving state based on a signal received from the vehicle-side computer 5 by the communication unit 34 via the in-vehicle communication network 7. The control unit 35 controls the ON / OFF of the relay switch 36 using the received signal from the vehicle-side computer 5 and noise detected by the noise detection unit 33. For example, even if the noise detection unit 33 does not detect noise generated when the vehicle 1 is started, the control unit 35 can determine that the vehicle 1 is in a driving state as long as it can receive a signal from the vehicle-side computer 5, and therefore does not output a signal to turn off the relay switch 36. Therefore, the power supply control device of this embodiment can supply power supply voltage to car accessories even when the vehicle is running on battery power or during idling stop.

[0054] The above-mentioned control unit 35 operates at least as follows. (a) The communication unit 34 receives (detects) a spontaneous output signal from the vehicle-side computer 5 via the in-vehicle communication network 7, for example, when the self-diagnosis signal is a CAN signal, and if the spontaneous output signal cannot be received, the following operation (b) is performed. (b) The noise detection unit 33 detects noise generated when the vehicle 1 starts from the voltage of the power supply terminal, and if noise generated when the vehicle 1 starts is detected, the following operation (c) is carried out. (c) The communication unit 34 sends, for example, a K-Line response request signal to the in-vehicle communication network 7 to the vehicle-side computer 5. That is, the control unit 35 sends a response request signal from the communication unit 34 to the vehicle-side computer 5 via the in-vehicle communication network 7, triggered by the noise detection unit 33 detecting noise generated when the vehicle 1 starts. (d) The communication unit 34 detects a response output signal (in response to a response request signal) from the vehicle-side computer 5 via the in-vehicle communication network 7, thereby detecting the wake-up of the vehicle-side computer 5. (e) When a spontaneous output signal or a response output signal is detected from the in-vehicle communication network 7, the supply of power supply voltage to the car accessory 20 is started.

[0055] As described above, after the noise detection unit 33 detects noise generated when the vehicle 1 is started, the control unit 35 uses the noise as a trigger to send a response request signal from the communication unit 34, thereby ensuring that the response request signal can be sent from the communication unit 34 when the in-vehicle communication network 7 on the vehicle 1 side is of a type that outputs a response output signal.

[0056] In addition, when the communication unit 34 detects a spontaneous output signal or when the noise detection unit 33 detects a response output signal in response to a response request signal when it detects noise generated when the vehicle 1 is started, the control unit 35 turns on the relay switch 36, thereby preventing unnecessary power consumption when the in-vehicle communication network 7 is a CAN or when the vehicle-side computer 5 is not operating and the vehicle 1 is not started.Whether the in-vehicle communication network 7 on the vehicle 1 side is a type that outputs a spontaneous output signal from the vehicle-side computer 5 or a type that outputs a response output signal, power can be supplied to the car accessory 20 with just one power supply control device 30.

[0057] Furthermore, the control unit 35 is provided with a timer unit 37 that measures a predetermined time, and after a response request signal is sent from the communication unit 34 using noise detected by the noise detection unit 33 as a trigger, the timer unit 37 measures the time, and turns on the relay switch 36 if the timing at which the communication unit 34 detects a response output signal in response to the response request signal is within the predetermined time defined by the timer unit 37. This allows power to be supplied to the car accessory 20 even when noise cannot be detected by the noise detection unit 33, such as when the car is running on battery power or during idling stop.

[0058] When the communication unit 34 detects a spontaneous output signal, the timer unit 37 measures the time since the communication unit 34 detected the spontaneous output signal. If the communication unit 34 detects the next spontaneous output signal within a predetermined time, the control unit 35 keeps the relay switch 36 ON and does not turn it OFF. If the in-vehicle communication network 7 is a CAN or the like, the spontaneous output signal from the vehicle computer 5 is output within a predetermined time. Therefore, if the time interval between the previous spontaneous output signal and the next spontaneous output signal is within a predetermined time specified in the standard of the in-vehicle communication network 7, by not turning the relay switch 36 OFF, it is possible to continue supplying power to the car accessory 20 while the battery 4 is running or during idling stop.

[0059] In addition, when the communication unit 34 is no longer able to detect a spontaneous output signal or a response output signal from the in-vehicle communication network 7, the control unit 35 controls the relay switch 36 to terminate the supply of power supply voltage to the car accessory 20, thereby stopping the supply of power supply voltage to the car accessory 20.This prevents unnecessary power consumption when the vehicle 1 is no longer in operation, for example, and the vehicle-side computer 5 no longer operates.

[0060] The OBD in-vehicle connector 6 is an SAE J1962 standard link connector (DLC), as shown in Figure 3. DLC connectors are available in two types: Type A and Type B. Type A connectors are installed within 1 foot (approximately 30 cm) of the vehicle's instrument panel (near the steering column) and are accessible from the driver's seat. Type B connectors are installed within 2.5 feet (approximately 75 cm) of the vehicle's instrument panel (near the center console, for example) and are accessible from either the driver's or passenger's seat. The DLC connector pinout (presence or absence of pins at each position) shown in Figure 3 indicates the type of in-vehicle communication network 7. The presence of pin 7 on the OBD in-vehicle connector 6 indicates a connection to the K Line. The presence of pins 6 and 14 on the OBD in-vehicle connector 6 indicates a connection to the CAN.

[0061] The method for determining whether a signal is received from the vehicle-side computer 5 is to first determine which terminal pin of the OBD in-vehicle connector 6 in Fig. 3 the signal is from. For example, if the in-vehicle communication network 7 is CAN, the signal is input to the terminal pin of Pin 6 (CAN High (J-2284) (3.5 to 2.5V)) and the terminal pin of Pin 14 (CAN Low (J-2284) (2.5 to 1.5V)) of the OBD in-vehicle connector 6. When this signal is input to the communication unit 34, the control unit 35 determines that it is a CAN signal because it is input to, for example, Pin 6 and Pin 14, and compares and confirms the levels of the CAN signals of Pin 6 and Pin 14 (based on the chassis ground level of Pin 4). Furthermore, it analyzes the sender address and the like included in the header of each received CAN signal to determine that it is a signal output from the vehicle-side computer 5. When it is confirmed that the vehicle-side computer 5 has woken up, the control unit 35 outputs a signal to turn on the relay switch 36, and supplies the power supply voltage of the terminal pin (Battery Power) of Pin 16 to the car accessory 20.

[0062] For example, if the in-vehicle communication network 7 is a K-Line, the control unit 35 sends a response request signal to the vehicle-side computer 5 from the communication unit 34 to the terminal pin (ISO9141-2 K-Line) of Pin 7 of the OBD in-vehicle connector 6, activates the timer unit 37, and waits for a response output signal from the vehicle-side computer 5. When a signal from the vehicle-side computer 5 is input to the communication unit 34, the control unit 35 determines that the signal is a K-Line signal because it is input to, for example, Pin 7, and compares the level of the K-Line signal with the chassis ground level of Pin 4. If the signal is received within a predetermined time specified by the K-Line standard, based on the time measured by the timer unit 37 from the transmission of the response request signal to the input of the signal, the control unit 35 determines that the signal is a response output signal. To more reliably confirm that the received signal is a response output signal from the vehicle-side computer 5, the sender address, etc. included in the header of each received K-Line signal may be analyzed. When it is confirmed that the vehicle-side computer 5 has woken up, the control unit 35 outputs a signal to turn on the relay switch 36, and supplies the power supply voltage of the terminal pin (Battery Power) of Pin 16 to the car accessory 20.

[0063] An OBD in-vehicle connector 6 such as that shown in Fig. 3 is provided in most vehicles 1. Normally, it is not easy to connect to the in-vehicle communication network 7 and to a power source other than the cigarette lighter (accessory socket), but by providing a connection means for connecting to the OBD in-vehicle connector 6 for self-diagnosis, which includes a connection terminal for the in-vehicle communication network 7 and a power supply terminal, such as the power input side connector 31 of this embodiment, the user can connect and disconnect the power source by themselves even if they do not have knowledge of in-vehicle wiring, and installation can be performed without having to go to a repair shop or the like.

[0064] Moreover, typical car accessories are connected to the cigarette lighter (accessory socket) or the power line of the vehicle 1. To prevent the car accessory from draining the battery of the parked vehicle, it is necessary to provide, for example, a noise detection unit 33 and a relay switch 36 inside the car accessory. In contrast, in this embodiment, the housing having the power supply control device 30's connecting means, the power supply input connector 31 and the power supply output connector 32, is provided with a communication unit 34, a noise detection unit 33, a control unit 35, a relay switch 36, and a timer unit 37, as shown in FIG. 2. This eliminates the need to provide a noise detection unit 33 inside the car accessory 20 that receives power from the power supply control device 30, allowing the car accessory 20 to be made smaller and preventing malfunctions caused by external noise entering the power supply line between the car accessory 20 and the car accessory 20.

[0065] In this way, the ON / OFF control of the power supply voltage supplied to the car accessory 20 is not determined solely based on noise as in the past, but also uses the signal output from the vehicle computer 5 to the in-vehicle communication network 7 when noise cannot be detected, making it possible to determine whether the vehicle 1 is running on battery 4 or in idling stop, something that was not possible in the past. Therefore, in a hybrid car (HV) or a vehicle 1 with an engine 2 that has an idling stop function, power supply power can be reliably supplied to the car accessory 20 even if the function to stop the engine is used while driving, and the noise detection unit 33 can accurately detect not only the restart of the engine 2 but also the start of the vehicle 1 running on battery power.

[0066] Second Embodiment For example, if the vehicle 1 has a security function such as an immobilizer, the security function of the vehicle 1 must be deactivated before starting the vehicle 1 in order to generate noise including a voltage drop at the time of starting the vehicle 1. Otherwise, the security function of the vehicle 1 may mistakenly determine that the process of starting the vehicle is a theft or the like.

[0067] The control unit 35 of the second embodiment detects, via the communication unit 34, a predetermined signal that is not output from the vehicle-side computer 5 when, for example, the security function of the vehicle 1 is ON and the vehicle is in a state where it cannot start traveling, but is output from the vehicle-side computer 5 only when the security function is OFF and the vehicle is in a state where it can start traveling. The control unit 35 confirms that the communication unit 34 has received the predetermined signal from the vehicle-side computer 5, that is, when the communication unit 34 changes from being unable to receive the predetermined signal to being able to receive it, and thereafter the noise detection unit 33 detects noise generated when the vehicle 1 starts, the control unit 35 outputs a signal to turn on the relay switch 36. This makes it possible to reliably prevent erroneous determination of the security function.

[0068] <Third embodiment> A vehicle 1 is typically equipped with multiple in-vehicle communication networks 7. Examples of the multiple in-vehicle communication networks 7 include the above-mentioned CAN, K Line, and proprietary standards (LIN, BEAN, etc.) of each manufacturer. The in-vehicle communication networks 7 of each manufacturer's proprietary standards are either a type that outputs a spontaneous output signal or a type that outputs a response output signal. The communication unit 34 of the third embodiment is connected to both an in-vehicle communication network 7 that outputs a spontaneous output signal from the vehicle-side computer 5, and an in-vehicle communication network 7 that, unlike the above, outputs a response output signal from the vehicle-side computer 5. The communication unit 34 communicates with the vehicle-side computer 5 via either of the above-mentioned in-vehicle communication networks 7. Which of the two in-vehicle communication networks 7 the vehicle-side computer 5 is connected to varies depending on the manufacturer and the vehicle model.

[0069] The power supply control device 30 that supplies power to car accessories needs to be versatile because it can be installed in any vehicle model. Versatility means that it can be compatible with both the in-vehicle communication network 7 for spontaneous output signals and the in-vehicle communication network 7 for response output signals. More specifically, it means that at least the communication unit 34 can be connected to both the in-vehicle communication network 7 for spontaneous output signals and the in-vehicle communication network 7 for response output signals. In this way, in the case of this embodiment, even a single power supply control device 30 can supply power to the car accessory 20 for both vehicle models whose in-vehicle communication network 7 uses spontaneous output signals and vehicle models whose in-vehicle communication network 7 uses response output signals.

[0070] <Fourth embodiment> In the fourth embodiment, in addition to the configuration in which the communication unit 34 is capable of connecting to and communicating with a plurality of different in-vehicle communication networks 7 as in the third embodiment described above, the control unit 35 monitors the plurality of different in-vehicle communication networks 7 connected to the communication unit 34. The control unit 35 then detects which of the plurality of different connected in-vehicle communication networks 7 the communication unit 34 can communicate with, and determines whether to turn the relay switch 36 on or off using information from the in-vehicle communication network 7 that the communication unit 34 can communicate with.

[0071] The control unit 35 of this embodiment can detect and use an in-vehicle communication network 7 with which it can communicate among multiple different in-vehicle communication networks 7 connected to the communication unit 34, so that for vehicle models having a wide variety of in-vehicle communication networks 7, power can be supplied to the car accessory 20 with only one power control device 30.

[0072] Fifth Embodiment When an electric vehicle (EV) or a hybrid car (HV) is running on battery power, or when a vehicle with an engine is idling-stop, noise is not generated from the engine, and therefore noise is not detected by the noise detection unit 33. Therefore, the control unit 35 of the fifth embodiment does not use the output signal of the noise detection unit 33, but instead turns on the relay switch 36 when it receives a signal from the vehicle-side computer 5, and turns off the relay switch 36 when it is no longer able to receive a signal from the vehicle-side computer 5. In other words, the control unit 35 of this embodiment turns on the power supply voltage supplied to the car accessory 20 when it receives a signal from the vehicle-side computer 5, not when it detects noise from the power supply voltage, and turns off the power supply voltage supplied to the car accessory 20 when it is no longer able to receive a signal from the vehicle-side computer 5.

[0073] When a signal from the vehicle-side computer 5 can be received, the vehicle-side computer 5 is naturally supplied with power and is awake. When the vehicle-side computer 5 is awake, it is considered that the vehicle is running or there is an occupant in the vehicle 1 with the ignition key turned on, and there is a demand for the car accessory. The signal from the vehicle-side computer 5 can be determined using the method described in the first embodiment. As described above, by turning on the power supply voltage supplied to the car accessory 20 when the vehicle-side computer 5 is awake, the car accessory 20 can be used when the vehicle is running or there is an occupant in the vehicle 1, even in the case of a hybrid car (HV) or a car with an idling stop function.

[0074] Sixth Embodiment For example, vehicle 1 is equipped with engine 2, timer unit 37 measures the maximum occurrence interval of noise generated by an alternator armature that varies with engine speed as the predetermined time, and filter 42 of noise detection unit 33 is changed to a filter that matches the noise frequency of the alternator. Then, control unit 35 prevents relay switch 36 from being turned off if noise detection unit 33 can detect the next noise within the predetermined time set by timer unit 37 after the previous noise was detected by noise detection unit 33.

[0075] In this embodiment, the relay switch 36 is not turned off while the noise detection unit 33 detects continuous noise such as alternator noise. Therefore, in the vehicle 1 equipped with the engine 2, power can be continuously supplied to the car accessory 20 while the engine 2 is running. <Another embodiment> (1) The power supply control device 30 may be provided inside a car accessory. For example, the power supply control device 30 may be provided inside the main body of a car accessory such as a radar detector or a fuel consumption meter. (2) The power supply control device 30 may be provided in a housing that is integrated with the OBD in-vehicle connector 6. (3) The power source is not limited to that obtained from the OBD in-vehicle connector 6, but may be variously configured, such as that obtained directly from the battery. [Explanation of symbols]

[0076] 1 vehicle, 2 engines, 3 alternators, 4 batteries, 5 vehicle-side computer, 6 OBD (On-Board diagnostics) in-car connector, 7 In-vehicle communication network, 8, 9 tires, 10, 11 Rotation sensor, 12, 13 Engine sensors (vibration, heat, rotation), 20 Car accessories, 21 Power connector, 30 Power supply control device, 31 Power input connector, 32 Power output connector, 33 noise detection unit (noise detection means), 34 Communication Department (communication means), 35 control unit (control means), 36 relay switch (switch), 37 timer section (timer means), 41 AC component passing circuit, 42 filters, 43 Amplification circuit, 44 Rectifier circuit, 45 DC conversion circuit.

Claims

1. A power supply control device having a function of terminating the supply of power from a vehicle to a car accessory when a spontaneous output signal from an in-vehicle communication network can no longer be detected, A power supply control device having the function of measuring the time since detecting a spontaneous output signal from an in-vehicle communication network, and if the next spontaneous output signal is detected within a predetermined time, continuing to supply power from the vehicle to the car accessories while the vehicle is idling stopped by not turning off the supply of power from the vehicle to the car accessories.

2. A power supply control device as described in claim 1, which has the function of continuing to supply power from the vehicle to the car accessories while the vehicle is idling stopped by not turning off the supply of power from the vehicle to the car accessories if the time interval from the previous spontaneous output signal to the next spontaneous output signal is within a predetermined time specified in the standard for the in-vehicle communication network.

3. A power supply control device as described in claim 1 or 2, which is configured to be connectable to both an in-vehicle communication network that outputs a spontaneous output signal from a vehicle-side computer and an in-vehicle communication network that outputs a response output signal from the vehicle-side computer in response to a response request signal, and which has a function of checking whether the connected in-vehicle communication network is a network that outputs the spontaneous output signal from the vehicle-side computer or a network that outputs a response output signal in response to a response request signal, and when it is a network that outputs a response output signal in response to a response request signal, has a function of terminating the supply of power supply voltage to the car accessory at predetermined time intervals when a response output signal can no longer be detected in response to the response request signal output by the in-vehicle communication network 7.

4. A program for causing a computer to realize the functions of the power supply control device according to any one of claims 1 to 3.

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