JP2015136211A - Power circuit and on-vehicle apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power circuit capable of preventing functional stall of an on-vehicle apparatus which possibly occurs at starting from an idling stop with a simple configuration.SOLUTION: A power circuit (2) in which a circuit group in need of initialization that requires the initialization processing at starting and a circuit group without the need for initialization that requires no initialization processing at starting coexist, and which is mounted on an on-vehicle apparatus (1) operated by receiving power from an on-vehicle battery includes: a first regulator (21) and a second regulator (22). The first regulator receives the power from the on-vehicle battery and converts the received voltage into a preset first supply voltage to supply the voltage to the circuit group without the need for initialization. The second regulator receives the power from the on-vehicle battery and converts the received voltage into a preset second supply voltage which is preset to be lower than the first supply voltage to supply the voltage to at least the circuit group in need of initialization.

Description

  The present invention relates to an in-vehicle device mounted on an idling stop vehicle and a power supply circuit mounted in the in-vehicle device.

  For the purpose of reducing fuel consumption and reducing emissions, an idling stop vehicle in which the engine is temporarily stopped temporarily when the vehicle is stopped, such as waiting for a signal, has been put into practical use. In this type of vehicle, the engine is automatically stopped when it is estimated that the vehicle is stopped based on predetermined idle determination information such as the vehicle speed and the accelerator opening, and then the engine start condition indicating the driver's intention to start When is established, the engine is automatically started by the starter.

  Generally, since the power consumption of the starter for starting the engine is large, there may be a phenomenon that the voltage of the battery output system temporarily decreases at the moment of starting the engine. When such a voltage drop occurs, there is a possibility that a microcomputer used for an electric device in the vehicle is reset. Then, once the microcomputer is reset, various initialization processes performed at the time of start-up are executed again, so that it takes time to restart, and the function assigned to the microcomputer cannot be used during that time.

  For example, it is conceivable to perform control by acquiring driving support information by wireless communication with an external infrastructure while waiting for a signal and performing idle control, and confirming whether the signal is really changing from red to blue. However, in the above apparatus, there is a possibility that the microcomputer is reset at the timing when the vehicle is started, and in this case, the above-described function cannot be used.

  On the other hand, a regulator that uses a booster circuit to compensate for the voltage drop due to the starter operation is known (see, for example, Patent Document 1).

JP 2005-237149 A

However, when the booster circuit is used, there is a problem that the device scale and the manufacturing cost increase.
The present invention has been made in view of these problems, and an object of the present invention is to provide a technique for suppressing a functional stop of an in-vehicle device that may occur at the time of startup from an idling stop state with a simple configuration.

  The power supply circuit of the present invention is a mixture of an initialization circuit group that requires initialization processing at startup and an initialization-unnecessary circuit group that does not require initialization processing at startup, and receives power from an in-vehicle battery. It is mounted on an in-vehicle device that operates and includes a first regulator and a second regulator.

  The first regulator receives power from the in-vehicle battery, converts the power supply voltage to a preset first power supply voltage, and supplies power to the initialization unnecessary circuit group. The second regulator receives power from the in-vehicle battery, converts the power supply voltage to a second voltage set lower than the first power supply voltage, and supplies power to at least the initialization circuit group required.

  According to such a configuration, each of the first regulator and the second regulator operates by receiving power directly from the vehicle-mounted battery, and therefore is connected so that the output of the first regulator becomes the input of the second regulator. Unlike the case, even when the power supply by the first regulator is stopped, the power supply by the second regulator can be continued.

Moreover, the initialization-unnecessary circuit group that receives power from the first regulator can immediately resume operation without performing initialization processing when the first regulator resumes power supply.
For example, the power supply circuit of the present invention is applied to an in-vehicle device that performs vehicle-to-vehicle communication and road-to-vehicle communication in an idling stop vehicle. Can be considered as an initialization circuit group required. In this case, even if the wireless communication device temporarily stops functioning due to a decrease in battery voltage, the sequential circuit and microcomputer stop functioning unless the battery voltage decreases to the extent that the second regulator stops power supply. There is nothing. For this reason, the process can be resumed immediately when the battery voltage is recovered and the wireless communication device can operate.

  As described above, according to the present invention, without using a large-scale booster circuit or the like, the microcomputer or the like constituting the in-vehicle device equipped with the power supply circuit is reset at the start-up from the idling stop state for a long time. It is possible to prevent the function from being stopped for a long time.

  In addition, the code | symbol in the parenthesis described in the claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is limited is not.

  Further, the present invention can be realized in various forms such as the above-described power supply circuit and in-vehicle device, as well as a system including the in-vehicle device as a component.

It is a block diagram which shows schematic structure of a vehicle-mounted apparatus. It is explanatory drawing which shows the structure of a power supply circuit, and an electric power feeding system.

Hereinafter, an embodiment of an in-vehicle device 1 to which the present invention is applied will be described with reference to the drawings.
This in-vehicle device 1 is used by being mounted on a vehicle that performs idling stop, uses an infrastructure cooperation system, acquires various types of information by vehicle-to-vehicle communication or road-to-vehicle communication, and provides driving assistance based on the acquired information. It generates various information to be used.

<Overall configuration>
As shown in FIG. 1, the in-vehicle device 1 includes a power supply circuit 2, a CAN driver / receiver 3, a CAN microcomputer (microcomputer) 4, a GPS module 5, an RF module 6, a main microcomputer 7, a flash memory (FLASH) 8, and a DRAM 9. Is provided.

  The power supply circuit 2 receives power supply from the in-vehicle battery, generates a plurality of types of power supply outputs whose voltages are lower than the battery voltage + B (for example, 12V), and supplies the power supply outputs to each unit of the in-vehicle device 1. Here, six types of power supply outputs V50 (= 5.0 V), V33 (= 3.3 V), V18 (= 1.8 V), V15 (= 1.5 V), V13 (= 1.3 V), V12 (= 1.2V) is generated.

  The CAN driver / receiver 3 transmits and receives signals via a CAN bus installed in the vehicle. The CAN microcomputer 4 executes communication processing according to the CAN protocol. The GPS module 5 receives a positioning signal from an artificial satellite for GPS (Global Positioning System) via a GPS antenna 11 mounted on the vehicle, and based on the received positioning signal, the position (latitude and longitude) of the host vehicle is received. ) And the detection result is output to the main microcomputer 7.

  The RF module 6 wirelessly communicates with a nearby vehicle equipped with a communication device existing around the host vehicle or a communication device (roadside machine) installed on the roadside via a communication antenna 12 mounted on the vehicle. This is a module for realizing inter-vehicle communication and road-vehicle communication. The RF module 6 generates a transmission signal by modulating a transmission power amplifier (PA) 61 that amplifies a transmission signal, a low noise amplifier (LNA) 62 that amplifies a reception signal, and transmission data supplied from the main microcomputer 7. A modem (MODEM) 63 that generates reception data obtained by demodulating the reception signal and supplies the reception data to the main microcomputer 7 is configured.

  The flash memory 8 is a nonvolatile storage device capable of rewriting stored contents, and stores a program executed by the main microcomputer 7, setting data by a user, and the like. The DRAM 9 is a volatile storage device and stores temporary processing data and the like.

  The main microcomputer 7 is based on the position information of the own vehicle acquired from the GPS module 5 and environmental information around the own vehicle acquired via the RF module 6 (behavior of nearby vehicles, traffic infrastructure such as traffic lights, etc.). Then, various types of information used for driving support are generated, and processing to be provided to other in-vehicle devices via the CAN bus is executed. The main microcomputer 7 has a CPU core 71 for executing processing according to a program, an input / output circuit (I / O) 72 for inputting / outputting signals to / from each part other than the main microcomputer 7, and a phase for generating a clock signal necessary for the operation. The circuit includes a synchronous circuit (PLL) 73, a peripheral circuit 74 including a memory control circuit for controlling refresh of the DRAM 9 and rewriting of the FLASH 8, and the like.

Since the configuration other than the power supply circuit 2 is well known, a detailed description thereof will be omitted.
<Power supply circuit>
The power supply circuit 2 includes six regulators 21 to 26 having different output voltages, as indicated by thick lines in FIG.

  The regulator 21 is configured by a low-loss linear regulator, and operates by receiving power supply (battery voltage + B) from the vehicle-mounted battery to generate a power supply output V50. The power supply output V50 is supplied to the transmission PA 61 of the RF module 6, the CAN driver / receiver 3, and the like.

  The regulator 22 is configured by a switching regulator, operates by receiving power supply from the in-vehicle battery, and generates a power supply output V33. This power supply output V33 is supplied to the regulators 23 to 26 in addition to being supplied to the I / O 72 of the main microcomputer 7, the FLASH 8, the GPS module 5, the LNA 62 of the RF module 6, and the like.

  The regulator 23 is constituted by a linear regulator, and operates by receiving power supply (power supply output V33) from the regulator 22 to generate a power supply output V18. The power supply output V18 is supplied to the DRAM 9 and the peripheral circuit 73 of the main microcomputer 7.

  The regulator 24 is configured by a linear regulator, and operates by receiving power supply (power supply output V33) from the regulator 22 to generate a power supply output V15. The power supply output V15 is supplied to the PLL 73 of the main microcomputer 7 and the like.

  The regulator 25 is configured by a linear regulator, and operates by receiving power supply (power supply output V33) from the regulator 22 to generate a power supply output V12. The power supply output V12 is supplied to the MODEM 63 of the RF module 6 and the like.

  The regulator 26 is configured by a linear regulator, and operates by receiving power supply (power supply output V33) from the regulator 22 to generate a power supply output V13. The power supply output V13 is supplied to the CPU core 71 of the main microcomputer 7 and the like.

Note that diodes D1 and D2 for backflow prevention and capacitors C1 and C2 for smoothing are connected to the inputs of regulators 21 and 22 that receive power directly from the vehicle battery.
Here, among each unit (circuit) that operates by receiving power supply from the power supply circuit 2, it is composed of an analog circuit whose output is uniquely determined according to the current input regardless of the past input, and after the power is turned on or something Circuits that immediately start operation without requiring an initialization process at the time of activation after reset due to a cause are collectively referred to as an initialization unnecessary circuit group. Further, a circuit composed of sequential circuits and requiring an initialization process at the time of startup is called an initialization circuit group required.

  The transmission PA 61 and the CAN driver / receiver 3 that operate by receiving power supply from the regulator 21 (power supply output V50) belong to the initialization unnecessary circuit group. In other words, the circuits that operate upon receiving the power supply output V50 are limited to those belonging to the initialization unnecessary circuit group, and at least the circuits belonging to the initialization circuit group required include the power supply from the regulator 22 (power supply output V33) or the regulator 22 It is configured to operate by receiving power supply (power supply outputs V18, V15, V13, V12) from regulators 23 to 26 provided downstream.

<Operation>
In the vehicle-mounted device 1 configured as described above, when the battery voltage + B is equal to or higher than the lower limit input voltage TH1 (TH1> 5V) of the regulator 21, power is supplied to all parts of the vehicle-mounted device 1. When the battery voltage + B becomes lower than the lower limit input voltage TH1 of the regulator 21, the power supply output V50 is stopped and the operations of the transmission PA 61 and the CAN driver / receiver 3 are also stopped. That is, the communication function using the CAN bus and the communication function using the RF module 6 cannot be used. At this time, if the battery voltage + B is equal to or higher than the lower limit input voltage TH2 (TH1>TH2> 3.3V) of the regulator 22, the power supply output V33 is generated, so that each unit other than the transmission PA 61 and the CAN driver / receiver 3 operates. Continue. Further, when the battery voltage + B becomes smaller than the lower limit input voltage TH2 of the regulator 22, the power supply output V33 is stopped, so that the operation of all parts of the in-vehicle device 1 is stopped.

<Effect>
As described above, in the power supply circuit 2 of the in-vehicle device 1, the regulators 21 and 22 operate by receiving power directly from the in-vehicle battery, so that the output of the regulator 21 is connected to the input of the regulator 22. Unlike the case, even when the power supply (power supply output V50) by the regulator 21 is stopped due to the decrease in the battery voltage + B, the power supply by the regulator 22 (power supply output V33) is performed as long as the battery voltage + B does not fall below the lower limit input voltage TH2. Can continue.

  In addition, since the parts that receive power supply from the regulator 21 are limited to those belonging to the initialization unnecessary circuit group, when the power supply from the regulator 21 is resumed, the operation can be resumed immediately without performing the initialization process. .

  Here, for example, a vehicle equipped with the in-vehicle device 1 is idling stopped while waiting for a traffic light, and then an engine start condition indicating a driver's intention to start is established, and a starter for starting the engine is operated, whereby the battery Consider a situation where the voltage + B is temporarily reduced. In addition, the main microcomputer 7 acquires the state of a traffic light, etc. by road-to-vehicle communication, determines whether or not it is really possible to start, and executes a driving support process using the determination result. To do.

  In this case, even if the battery voltage + B falls below the lower limit input voltage TH1 of the regulator 21, unless the voltage is lower than the lower limit input voltage TH2 of the regulator 22, the part where the operation is stopped (reset) is the initialization unnecessary circuit group. The operation of the part belonging to only the part belonging to the initialization circuit group required continues. As a result, inter-vehicle communication using the RF module 6 and road-vehicle communication functions and communication functions with other in-vehicle devices using the CAN bus cannot be temporarily used. However, if the battery voltage + B returns to the lower limit input voltage TH1 or more, the portion that has stopped operating immediately restarts operation without performing initialization processing. That is, it is possible to suppress the occurrence of a situation in which the initialization circuit group required is reset in a situation that is a target of such driving support processing, and the function of the in-vehicle device 1 is stopped during the time required for the restart. it can.

<Other embodiments>
As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention can take a various form, without being limited to the said embodiment.

  (1) In the above embodiment, two regulators that receive power directly from the in-vehicle battery are provided, but three or more regulators may be provided. In this case, there may be a plurality of ones corresponding to the first regulator or a plurality of ones corresponding to the second regulator.

  (2) Each component of the present invention is conceptual and is not limited to the above embodiment. For example, the functions of one component may be distributed to a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment.

  DESCRIPTION OF SYMBOLS 1 ... In-vehicle apparatus 2 ... Power supply circuit 3 ... CAN driver / receiver 4 ... CAN microcomputer 5 ... GPS module 6 ... RF module 7 ... Main microcomputer 8 ... Flash memory (FLASH) 9 ... DRAM 11 ... GPS antenna 12 ... Communication antenna 21 -26 ... Regulator 61 ... Transmission power amplifier (transmission PA) 62 ... Low noise amplifier (LNA) 63 ... Modem (MODEM) 71 ... CPU core 72 ... Input / output circuit (I / O) 73 ... Phase synchronization circuit (PLL) 74 ... Peripheral circuit C1, C2 ... Capacitor D1, D2 ... Diode

Claims (6)

Installed in the in-vehicle device (1), which includes a group of initialization circuits that require initialization processing at startup and a group of initialization-free circuits that do not require initialization processing at startup. A power supply circuit (2),
A first regulator (21) that receives power from the in-vehicle battery, converts the power supply voltage to a preset first power supply voltage, and supplies power to the initialization unnecessary circuit group;
A second regulator (22) that receives power from the in-vehicle battery, converts the power supply voltage into a second voltage set lower than the first power supply voltage, and supplies power to at least the initialization circuit group required;
A power supply circuit comprising:   The power supply circuit according to claim 1, wherein a linear regulator is used as the first regulator.   The power supply circuit according to claim 1, wherein a switching regulator is used as the second regulator. An initialization circuit group (5, 63, 71, 73, 74) that requires initialization processing at the time of startup;
Initialization unnecessary circuit group (3, 61) which does not require initialization processing at the time of startup,
A power supply circuit (2) that operates by receiving power from a vehicle-mounted battery and supplies power to the initialization circuit group and the initialization-unnecessary circuit group;
With
The power supply circuit is
A first regulator (21) that receives power from the in-vehicle battery, converts the power supply voltage to a preset first power supply voltage, and supplies power to the initialization unnecessary circuit group;
A second regulator (22) that receives power from the in-vehicle battery, converts the power supply voltage into a second voltage set lower than the first power supply voltage, and supplies power to at least the initialization circuit group required;
A vehicle-mounted device comprising:   The in-vehicle device according to claim 4, wherein the initialization unnecessary circuit group includes an analog circuit that performs at least one of vehicle-to-vehicle communication or road-to-vehicle communication.   The in-vehicle device according to claim 4, wherein the initialization circuit group required includes a sequential circuit.

Images