216, and exchanges a communication signal or a communication signal on which power is superimposed. In addition, the power supply superimposition filter 304 is connected to the power supply switcher 302 via a power supply line 305 and is connected to the transceiver 303 via a communication line 308. In the power supply superimposition filter 304, only direct current (DC) power and power having a frequency near DC pass between the communication line 216 and the power supply line 305, and only a high-frequency communication signal passes between the communication line 216 and the communication line 308. The power supply superimposition filter 304 is configured using, for example, power over datalines (PoDL), and separates and superimposes a communication signal and power. In the PoDL, direct current (DC) power is superimposed on a signal (differential) and transmitted using a pair of twisted cables.

The power supply switcher 302 receives the power of the power supply 201 supplied via the power supply harness 207 and the power of the power supply 202 supplied via the power supply line 305. Then, the power supply switcher 302 internally monitors the voltage passing through the power supply harness 207 and the voltage passing through the power supply line 305, and determines and switches which voltage is connected to the output. Accordingly, the power supply switcher 302 supplies power to the ECU core unit 301 via a power supply line 307, to the transceiver 303 via a power supply line 306, to the sensor 231 via the power supply line 241, and to the actuator 232 via the power supply line 243.

In a case where the power supply 201 is normal, the power supply switcher 302 supplies power from the power supply harness 207 to the ECU core unit 301, the transceiver 303, the sensor 231, and the actuator 232. On the other hand, in a case where the power supply 201 has failed and the power supply 202 is normal, the power supply switcher 302 supplies the power transmitted through the power supply line 305 to the ECU core unit 301, the transceiver 303, the sensor 231, and the actuator 232. In addition, since the power supply switcher 302 can obtain information indicating that the power supply 201 has failed (power supply failure information), the power supply failure information can be transmitted to the ECU core unit 301 via a communication line 309 to share the power supply failure information with other ECUs.

As described above, when the power supply of the first voltage from the first power supply (power supply 201) to the first control circuit (ECU core unit 301) is interrupted, the first control circuit notifies an external device (for example, another ECU) that the first power supply is abnormal. As a result, for example, another in-vehicle ECU can perform appropriate control such as operation continuation control in response to the abnormality of the first power supply.

The transceiver 303 communicates with the ECU 204 via the communication line 216 via the communication line 308 and the power supply superimposition filter 304 and the communication line 220. In addition, the transceiver 303 communicates with the ECU 205 via the communication line 215 and the communication line 219. Then, the transceiver 303 exchanges a transmission signal and a reception signal for another ECU with the ECU core unit 301 via a communication line 310.

The ECU core unit 301 controls the transceiver 303 via the communication line 310, and exchanges data with the ECU 204, the ECU 205, and the ECU 206 (FIG. 2) via the transceiver 303. The ECU 203 and the ECU 206 can communicate with each other via another ECU 204 or ECU 205 by designating a transmission source and a transmission destination to each other by routing. In addition, the ECU core unit 301 performs control and data transmission/reception with respect to the sensor 231 and the actuator 232, and performs data processing.

For example, the ECU core unit 301 may include a memory (ROM and RAM) and a nonvolatile storage in addition to a processor not illustrated. For example, a processor such as a central processing unit (CPU) or a micro-processing unit (MPU) can be used as the processor of the ECU core unit 301. The processor executes the computer program stored in the ROM or the nonvolatile storage, thereby implementing the function of the ECU core unit in the embodiment of the present invention.

[Configuration of Power Supply Switcher]

Next, a configuration of the power supply switcher included in the electronic control device (ECU) according to the present embodiment will be described with reference to FIG. 4.

FIG. 4 is a block diagram illustrating a configuration example of the power supply switcher 302 included in the ECU 203. The power supply switcher 302 includes an own power supply switch 401, an other load switch 402, an other power supply switch 403, and a power supply circuit 404. A solid line without an arrow connected to the own power supply switch 401, the other load switch 402, and the other power supply switch 403 represents a power supply application of power, and a solid line with an arrow represents a power control application.

The own power supply switch 401 is a circuit that monitors the voltage of the power supply harness 207, turns on the internal switch when the voltage is equal to or higher than a preset threshold voltage, conducts the power supply harness 207 and a power supply line 405, and supplies power to the power supply circuit 404 through the power supply line 405. When the voltage of the power supply harness 207 falls below the threshold voltage, the own power supply switch 401 turns off the internal switch to cut off the connection between the power supply harness 207 and the power supply line 405. Further, the own power supply switch 401 outputs a signal based on the comparison result between the voltage from the power supply harness 207 and the threshold voltage to the ECU core unit 301 via the communication line 309. This signal corresponds to the power supply failure information described in FIG. 3.

The other load switch 402 is a circuit that monitors the voltages of the power supply harness 207 and the power supply line 305, turns on the internal switch when both the voltages are equal to or higher than a preset threshold voltage, and conducts the power supply harness 207 and the power supply line 305. When either the voltage of the power supply harness 207 or the voltage of the power supply line 305 falls below the threshold voltage, the other load switch 402 turns off the internal switch to cut off the connection between the power supply harness 207 and the power supply line 305.

The other power supply switch 403 is a circuit that monitors the voltage of the power supply harness 207, turns off the internal switch when the voltage is equal to or higher than a preset threshold voltage, cut off the connection between the power supply line 305 and the power supply line 405, and does not supply power to the power supply circuit 404. When the voltage of the power supply harness 207 falls below the threshold voltage, the other power supply switch 403 conducts between the power supply line 305 and the power supply line 405, and supplies power to the power supply circuit 404 through the power supply line 405.

The power supply circuit 404 converts the voltage of the power transmitted from the power supply line 405 according to the supply destination, and supplies the power via each of the power supply line 306, the power supply line 307, the power supply line 241, and the power supply line 243.

[First Example of Each Switch]

Here, a first example of the own power supply switch, the other load switch, and the other power supply switch constituting the power supply switcher 302 in the present embodiment will be described with reference to FIG. 5.

FIG. 5 is a circuit diagram illustrating the first example of the own power supply switch 401, the other load switch 402, and the other power supply switch 403 constituting the power supply switcher 302. The own power supply switch 401 includes a metal oxide semiconductor field-effect transistor (MOSFET) 501, a comparator 502, and a threshold voltage source 503.

The MOSFET 501 is an example of a P-type MOSFET, and in a high-voltage type, a diode is connected between a drain and a source. It similarly applies to the MOSFETs used in the following switches.

The comparator 502 compares the voltage from the power supply harness 207 with the threshold voltage of the threshold voltage source 503, and sets the output to the Low level when the voltage from the power supply harness 207 is equal to or higher than the threshold voltage, turns on the MOSFET 501, and conducts the power supply harness 207 and the power supply line 405. On the other hand, if the voltage from the power supply harness 207 is lower than the threshold voltage, the comparator 502 sets the output to the High level, turns off the MOSFET 501, and cuts off the connection between the power supply harness 207 and the power supply line 405. The output of the comparator 502 is transmitted to the ECU core unit 301 via the communication line 309.

The other load switch 402 includes a MOSFET 504, an OR circuit 505, a comparator 506, a threshold voltage source 507, a comparator 508, and a threshold voltage source 509. The comparator 506 compares the voltage of the power supply 201 from the power supply harness 207 with the threshold voltage of the threshold voltage source 507, and sets the output to the Low level when the voltage from the power supply harness 207 is equal to or higher than the threshold voltage, and conversely sets the output to the High level when the voltage from the power supply harness 207 is lower than the threshold voltage.

The comparator 508 compares the voltage of the power supply 202 from the power supply line 305 with the threshold voltage of the threshold voltage source 509, and sets the output to the Low level when the voltage from the power supply line 305 is equal to or higher than the threshold voltage, and conversely sets the output to the High level when the voltage from the power supply line 305 is lower than the threshold voltage.

The OR circuit 505 is a logical sum circuit that sets its own output to the High level when either the output voltage of the comparator 506 or the output voltage of the comparator 508 is at the High level, and sets its own output to the Low level when both the output voltages are at the Low level.

The MOSFET 504 is turned on when the output of the OR circuit 505 is at the Low level, and conducts the power supply harness 207 and the power supply line 305. On the other hand, the MOSFET 504 is turned off when the output of the OR circuit 505 is at the High level, and cuts off the connection between the power supply harness 207 and the power supply line 305.

The other power supply switch 403 includes only a MOSFET 510. Of course, a comparator may be used for the other power supply switch 403, similarly to the own power supply switch 401. Only when the voltage of the power supply harness 207 is lower than the voltage necessary for switching the MOSFET 510 with respect to the voltage of the power supply line 405 (the source-gate voltage is lower than the threshold voltage), the MOSFET 510 is turned on, and the power supply line 405 and the power supply line 305 are conducted.

In the initial state, since the voltage of the power supply line 405 starts in a low state, the MOSFET 501 and the MOSFET 510 are turned off. For example, the initial state is at the time of power supply activation, at the time of activation of the ECU 203, at the time of activation of the automobile, or the like. Here, in the MOSFET 501, since the diode is connected between the drain and the source, when the voltage of the power supply harness 207 becomes higher than the threshold voltage of the diode, the power supply line 405 and the power supply harness 207 are conducted, and the value of the voltage of the power supply line 405 increases, so that the MOSFET 501 is also turned on. In addition, it similarly applies to a case where the power supply line 305 is started in a low voltage state, and the MOSFET 504 is initially turned off, but the power supply harness 207 and the power supply line 305 are conducted via a diode connected between the drain and source of the MOSFET 504, the voltage value of the power supply line 305 increases, and the MOSFET 504 is also turned on.

According to the power supply switcher having the above configuration, it is possible to switch the power supply passing through the power supply harness and the power supply passing through the communication line to a high speed and a low loss when the power supply fails.

[Second Example of Each Switch]

Next, a second example of the own power supply switch, the other load switch, and the other power supply switch constituting the power supply switcher 302 in the present embodiment will be described with reference to FIG. 6.

FIG. 6 is a circuit diagram illustrating the second example of an own power supply switch 401A, an other load switch 402A, and an other power supply switch 403 constituting the power supply switcher 302. The configuration of the power supply switcher 302 illustrated in FIG. 6 is different from the power supply switcher 302 of the first example illustrated in FIG. 5 in that a level shifter (denoted as “LV” in the drawing) is used instead of the threshold voltage source, and the operation thereof is substantially the same as that of the first example.

The own power supply switch 401A includes a MOSFET 501, a comparator 502, and a level shifter 601. The level shifter 601 shifts the voltage from the power supply harness 207 by a preset voltage and outputs the voltage to the comparator 502. The comparator 502 outputs the Low level when the output voltage of the level shifter 601 is positive, and outputs the High level when the output voltage is negative, thereby controlling ON/OFF of the MOSFET 501. At that time, the output of the comparator 502 is transmitted to the ECU core unit 301 via the communication line 309.

The other load switch 402A includes a MOSFET 504, an OR circuit 505, a comparator 506, a level shifter 602, a comparator 508, and a level shifter 603. The level shifter 602 shifts the voltage from the power supply harness 207 by a preset voltage and outputs the voltage to the comparator 506. The comparator 506 outputs the Low level when the output voltage of the level shifter 602 is positive, and outputs the High level when the output voltage is negative. The level shifter 603 shifts the voltage from the power supply line 305 by a preset voltage and outputs the voltage to the comparator 508. The comparator 508 outputs the Low level when the output voltage of the level shifter 603 is positive, and outputs the High level when the output voltage is negative.

The OR circuit 505 controls ON/OFF of the MOSFET 504 by setting the output to the High level when any of the output voltages of the comparator 506 and the comparator 508 is at the High level, and setting the output to the Low level when any of the output voltages is at the Low level.

[Third Example of Each Switch]

Next, a third example of the own power supply switch, the other load switch, and the other power supply switch constituting the power supply switcher 302 in the present embodiment will be described with reference to FIG. 7.

FIG. 7 is a circuit diagram illustrating the third example of an own power supply switch 401B, an other load switch 402B, and an other power supply switch 403B constituting the power supply switcher 302. The configuration of the power supply switcher 302 illustrated in FIG. 7 is different from the power supply switcher 302 of the first example illustrated in FIG. 5 in that each switch is provided with a countermeasure for preventing current leakage due to a ground fault in the power supply line 405, the power supply line 305, and the connection destination thereof.

A P-type MOSFET 701 having a drain-source direction opposite to that of the MOSFET 501 is added to the own power supply switch 401B. In the example of FIG. 7, the drain of the MOSFET 501 and the drain of the MOSFET 701 are connected, and the gate of the MOSFET 701 is connected to the output terminal of the comparator 502.

In addition, a MOSFET 702 having a drain-source direction opposite to that of the MOSFET 504 is added to the other load switch 402B. In the example of FIG. 7, the drain of the MOSFET 504 and the drain of the MOSFET 702 are connected, and the gate of the MOSFET 702 is connected to the output terminal of the OR circuit 505. Then, the source of the MOSFET 701 of the own power supply switch 401B and the source of the MOSFET 702 of the other load switch 402B are connected. In addition, the sources of the MOSFET 701 and the MOSFET 702 are connected to the power supply harness 207.

Further, a MOSFET 703 having a drain-source direction opposite to that of the MOSFET 510 is added to the other power supply switch 403B. In the example of FIG. 7, the drain of the MOSFET 510 and the drain of the MOSFET 703 are connected, the source of the MOSFET 703 is connected to the power supply line 305, and the gate of the MOSFET 703 is connected to the power supply harness 207.

In the MOSFET 701, the MOSFET 702, and the MOSFET 703, the orientations of the diodes are opposite to those of the original MOSFET 501, MOSFET 504, and MOSFET 510. The occurrence of current leakage can be prevented by the diodes of the MOSFETs 701 to 703.

As described above, in the power supply switcher (power supply switcher 302) according to the present embodiment, the first switch circuit (own power supply switch 401B) includes the first switching element (MOSFET 501) that energizes between the first power supply (power supply 201) and the first control circuit (ECU core unit 301) when the voltage drop of the first voltage (voltage of the power supply 201) is smaller than the threshold, and the switching element (MOSFET 701) connected between the first power supply and the first control circuit in series with the first switching element and having the opposite polarity. In addition, the second switch circuit (other load switch 402B) includes the second switching element (MOSFET 504) that energizes between the first power supply and the communication line (communication line 216 (power supply line 305)) when the voltage drop of both the first voltage and the second voltage (voltage of power supply 202) is smaller than the threshold, and the switching element (MOSFET 702) connected between the first power supply and the communication line in series with the second switching element and having the opposite polarity. In addition, the power supply switch circuit (other power supply switch 403B) includes the third switching element (MOSFET 510) that energizes between the first control circuit and the communication line (communication line 216 (power supply line 305)) when the voltage drop of the first voltage is smaller than the threshold, and the switching element (MOSFET 703) connected between the first control circuit and the communication line in series with the third switching element and having the opposite polarity.

[Fourth Example of Each Switch]

Next, a fourth example of the own power supply switch, the other load switch, and the other power supply switch constituting the power supply switcher 302 in the present embodiment will be described with reference to FIG. 8.

FIG. 8 is a circuit diagram illustrating the fourth example of an own power supply switch 401C, an other load switch 402C, and the other power supply switch 403B constituting the power supply switcher 302. The configuration of the power supply switcher 302 illustrated in FIG. 8 is different from the power supply switcher 302 of the second example illustrated in FIG. 6 in that each switch is provided with a countermeasure for preventing current leakage due to a ground fault in the power supply line 405, the power supply line 305, and the connection destination thereof. That is, in the fourth example of the power supply switcher 302, countermeasures similar to those in the third example are taken.

In the own power supply switch 401C, the MOSFET 501 having a drain-source direction opposite to that of the MOSFET 501 is added between the drain of the MOSFET 701 and the power supply harness 207, and the gate of the MOSFET 701 is connected to the output terminal of the comparator 502.

In the other load switch 402C, the MOSFET 504 having a drain-source direction opposite to that of the MOSFET 504 is added between the drain of the MOSFET 702 and the power supply harness 207, and the gate of the MOSFET 702 is connected to the output terminal of the OR circuit 505.

Similarly to the third example of the power supply switcher 302 illustrated in FIG. 7, in the MOSFET 701, the MOSFET 702, and the MOSFET 703, the orientations of the diodes are opposite to those of the original MOSFET 501, MOSFET 504, and MOSFET 510. The occurrence of current leakage can be prevented by the diodes of the MOSFETs 701 to 703.

Note that a circuit of each switch of the power supply switcher 302 may be configured using an N-type MOSFET as the MOSFET of each switch described above. In addition, other switching elements may be used instead of the MOSFET. Hereinafter, in the present specification, in a case where the own power supply switches 401 to 401C are not distinguished or collectively referred to, it may be simply described as the “own power supply switch 401”. Similarly, the other load switches 402 to 402C may be referred to as “other load switch 402”, and the other power supply switches 403 and 403B may be referred to as “other power supply switch 403”.

As described above, the power supply system (power supply system 200 (ECU 203)) according to the first embodiment includes: the first control circuit (ECU core unit 301); the first power supply (power supply 201) that outputs the first voltage supplied to the first control circuit as the power supply voltage; the first switch circuit (own power supply switches 401 to 401C) that is connected to the first power supply (power supply harness 207) and the first control circuit and interrupts the power supply of the first voltage to the first control circuit; the second switch circuit (other load switches 402 to 402C) that is connected to the communication line (for example, communication line 216) used for communication between the first power supply and the second control circuit and interrupts the supply of the first voltage to the communication line; the second power supply (power supply 202) that outputs the second voltage supplied to the second control circuit as the power supply voltage; and the power supply switch circuit (other power supply switches 403 and 403B) that is connected to the first control circuit and the communication line and supplies the second voltage to the first control circuit via the communication line when the supply of the first voltage to the first control circuit is interrupted by the first switch circuit. Here, the power supply of the first voltage to the second control circuit and the power supply of the second voltage to the first control circuit are bidirectional power transmission using the communication line.

The first switch circuit interrupts the supply of the first voltage to the first control circuit in a case where the voltage drop of the first voltage is equal to or greater than the threshold, the second switch circuit interrupts the supply of the first voltage to the communication line in a case where the voltage drop of the first voltage is equal to or greater than the threshold, and the power supply switch circuit switches the supply source of the power supply voltage to the first control circuit from the first power supply to the second power supply.

According to the present embodiment having the above configuration, since the power supply source can be switched from the first power supply to the second power supply by bidirectional power transmission using the power supply redundancy technology, it is possible to realize power supply redundancy without increasing the number of power supply harnesses as in the related art.

In addition, in the power supply system (power supply system 200 (ECU 203)) according to the present embodiment, the first switch circuit (own power supply switches 401 to 401C) supplies the first voltage to the first control circuit in a case where the voltage drop of the first voltage is smaller than the threshold, the second switch circuit (other load switches 402 to 402C) supplies the first voltage to the communication line in a case where the voltage drop of the first voltage is smaller than the threshold and the voltage drop of the second voltage is equal to or greater than the threshold, and the power supply switch circuit (other power supply switches 403 and 403B) cuts off the communication line from the first control circuit.

According to the present embodiment having the above configuration, in a case where there is an abnormality in the second voltage of the second power supply, the first voltage can be supplied to the second control circuit by bidirectional power transmission using the power supply redundancy technology. Therefore, it is possible to realize power supply redundancy without increasing the number of power supply harnesses.

Second Embodiment

Next, a configuration of a power supply switcher included in an electronic control device (ECU) according to a second embodiment of the present invention will be described with reference to FIG. 9.

[Configuration of Power Supply Switcher]

FIG. 9 is a block diagram illustrating a configuration example of a power supply switcher 302A included in the ECU 203. The configuration of the power supply switcher 302A illustrated in FIG. 9 is different from the power supply switcher 302 illustrated in FIG. 4 in that determination control circuits (comparator, OR circuit, and the like in FIGS. 5 to 8) provided in the own power supply switch 401, the other load switch 402, and the other power supply switch 403 are integrated into one controller 907.

The power supply switcher 302A includes an own power supply switch 901, an other load switch 902, an other power supply switch 903, a controller 907, and a power supply circuit 404.

The own power supply switch 901, the other load switch 902, and the other power supply switch 903 are all configured using one MOSFET or two MOSFETs as illustrated in FIGS. 5 to 8. The own power supply switch 901, the other load switch 902, and the other power supply switch 903 have switching functions similar to those of the own power supply switch 401, the other load switch 402, and the other power supply switch 403 illustrated in FIG. 4.

The voltage from the power supply harness 207 and the voltage from the power supply line 305 are input to the controller 907. Then, the controller 907 controls the own power supply switch 901 via the communication line 309, the other load switch 902 via a control line 905, and the other power supply switch 903 via a control line 906 according to the voltage of the power supply harness 207 and the voltage of the power supply line 305.

In the own power supply switch 901 including one or two MOSFETs, a control signal from the controller 907 is input to the gate of each MOSFET via the communication line 309. In addition, in the other load switch 902 including one or two MOSFETs, the control signal from the controller 907 is input to the gate of each MOSFET through the control line 905. Further, in the other power supply switch 903 including one or two MOSFETs, a control signal from the controller 907 is input to the gate of each MOSFET via the control line 906.

[First Example of Controller]

Here, a first example of the controller 907 constituting the power supply switcher 302A in the present embodiment will be described with reference to FIG. 10.

FIG. 10 is a circuit diagram illustrating the first example of the controller 907 constituting the power supply switcher 302A.

The controller 907 includes a comparator 1001, a threshold voltage source 1002, a comparator 1003, a threshold voltage source 1004, an OR circuit 1005, and a NOT circuit 1006.

The comparator 1001 compares the voltage from the power supply harness 207 with the threshold voltage of the threshold voltage source 1002, and sets the output to the Low level when the voltage from the power supply harness 207 is equal to or higher than the threshold voltage, and conversely sets the output to the High level when the voltage from the power supply harness 207 is lower than the threshold voltage. The comparator 1001 outputs a signal corresponding to the comparison result to the communication line 309.

The comparator 1003 compares the voltage from the power supply line 305 with the threshold voltage of the threshold voltage source 1004, and sets the output to the Low level when the voltage from the power supply line 305 is equal to or higher than the threshold voltage, and conversely sets the output to the High level when the voltage from the power supply line 305 is lower than the threshold voltage.

The OR circuit 1005 sets the output to the High level when either the output voltage of the comparator 1001 or the output voltage of the comparator 1003 is at the High level, and sets the output to the Low level when both the output voltages are at the Low level. The OR circuit 1005 outputs a signal corresponding to the logic operation result to the control line 905 connected to the other load switch 902.

The NOT circuit 1006 inverts the output value of the comparator 1001 and outputs the inverted output value to the control line 906 connected to the other power supply switch 903. The NOT circuit 1006 outputs the High level when the output voltage of the comparator 1001 is at the Low level, and outputs the Low level when the output voltage of the comparator 1001 is at the High level.

[Second Example of Controller]

Next, a second example of the controller 907 constituting the power supply switcher 302A in the present embodiment will be described with reference to FIG. 11.

FIG. 11 is a circuit diagram illustrating the second example of the controller 907 constituting the power supply switcher 302A. The configuration of the controller 907A illustrated in FIG. 11 is different from the controller 907 of the first example illustrated in FIG. 10 in that a level shifter (denoted as “LV” in the drawing) is used instead of the threshold voltage source, and the operation is substantially the same as that of the first example.

The controller 907A includes a comparator 1001, a level shifter 1101, a comparator 1003, a level shifter 1102, an OR circuit 1005, and a NOT circuit 1006.

The level shifter 1101 shifts the voltage from the power supply harness 207 by a preset voltage and outputs the voltage to the comparator 1001. The comparator 1001 outputs the Low level when the output voltage of the level shifter 1101 is positive, and outputs the High level when the output voltage is negative.

The level shifter 1102 shifts the voltage from the power supply line 305 by a preset voltage and outputs the voltage to the comparator 1003. The comparator 1003 outputs the Low level when the output voltage of the level shifter 1102 is positive, and outputs the High level when the output voltage is negative.

The OR circuit 1005 outputs the High level when any of the output voltages of the comparator 1001 and the comparator 1003 is at the High level, and outputs the Low level when any of the output voltages is at the Low level. The NOT circuit 1006 inverts the output value of the comparator 1001. The NOT circuit 1006 outputs the signal at the High level when the signal is input at the Low level, and outputs the signal at the Low level when the signal is input at the high level.

[Third Example of Controller]

Next, a third example of the controller 907 constituting the power supply switcher 302A in the present embodiment will be described with reference to FIG. 12.

FIG. 12 is a circuit diagram illustrating the third example of the controller 907 constituting the power supply switcher 302A. A controller 907B illustrated in FIG. 12 includes an analog-to-digital converter (ADC) 1201, an ADC1202, and a microprocessor (denoted as “MCU” in the drawing) 1203. For example, a micro controller unit (MCU) can be used as the microprocessor 1203. In general, the MCU includes a processor, a memory such as a ROM and a RAM, an I/O, and the like. Since the controller 907B in the present embodiment can convert the voltages (analog signals) from the power supply harness 207 and the power supply line 305 into digital data, the control contents can be modified by programming.

The ADC1201 converts the value of the voltage from the power supply harness 207 into a digital value, and outputs the digital value to the microprocessor 1203. Furthermore, the ADC1202 converts the value of the voltage from the power supply line 305 into a digital value, and outputs the digital value to the microprocessor 1203.

The microprocessor 1203 receives the output of the ADC1201 and the output of the ADC1202. Then, when the output code (digital value of the voltage) of the ADC1201 is larger than the set code, the microprocessor 1203 sets the output to the communication line 309 to the Low level and sets the output to the control line 906 connected to the other power supply switch 903 to the High level. In addition, under other conditions, the microprocessor 1203 sets the output to the communication line 309 to the High level and sets the output to the control line 906 to the Low level. In addition, when either the output code of the ADC1201 or the output code of the ADC1202 is larger than the set code, the microprocessor 1203 sets the output to the control line 905 connected to the other load switch 902 to the High level, and sets the output to the control line 905 to the Low level under other conditions.

As described above, in the power supply switcher (power supply switcher 302A) of the power supply system (power supply system 200) according to the second embodiment, the determination control circuits (comparator, OR circuit, and the like in FIGS. 5 to 8) provided in the three switch circuits in the first embodiment are integrated into one controller (controllers 907 to 907B). Therefore, in the power supply system according to the present embodiment, the configuration of each switch circuit constituting the power supply switcher can be simplified.

Third Embodiment

Next, a configuration of a power supply system according to a third embodiment of the present invention will be described with reference to FIG. 13.

[Configuration of Power Supply System]

FIG. 13 is a system configuration diagram illustrating an example of power supply redundancy of the power supply system according to the third embodiment. While the power supply system 200 (FIG. 2) according to the first and second embodiments has a ring-type architecture using four ECUs 203 to 206, a power supply system 1300 according to the present embodiment has a star-type architecture using four ECUs 1303 to 1306. Here, an example in which four ECUs are provided is illustrated, but the basic connection manner does not change even if the number of ECUs increases. In this architecture, a central ECU (ECU 1303) and other ECUs (ECUs 1304 to 1306) are connected by a communication line. The star-type architecture has an advantage that communication lines can be reduced.

The power supply system 1300 includes a power supply 201, a power supply 202, an ECU 1303, an ECU 1304, an ECU 1305, an ECU 1306, power supply harnesses 207 to 208, power supply harnesses 211 to 212, communication lines 1311 to 1313 indicated by solid lines, and communication lines 1314 to 1316 indicated by broken lines. The communication lines 1311 to 1313 indicated by solid lines are power supply superimposing communication lines. In addition, the communication lines 1314 to 1316 indicated by broken lines are communication lines for communication. However, the same power supply superimposing communication line as the communication lines 1311 to 1313 may be used as the communication lines 1314 to 1316.

The power supply 201 supplies power to the ECU 1303 via the power supply harness 207 and supplies power to the ECU 1305 via the power supply harness 208. In addition, the power supply 202 supplies power to the ECU 1304 via the power supply harness 211 and supplies power to the ECU 1306 via the power supply harness 212.

The ECU 1303 and the ECU 1304 can supply power to each other by superimposing power via the communication line 1311. In a case where the power supply 201 fails, the power of the power supply 202 is supplied from the ECU 1304 to the ECU 1303 via the communication line 1311. Conversely, when the power supply 202 fails, the power of the power supply 201 is supplied from the ECU 1303 to the ECU 1304 via the communication line 1311.

In addition, it similarly applies to power transmission between the ECU 1303 and the ECU 1306, and the ECU 1303 and the ECU 1306 can supply power to each other by superimposing power via the communication line 1313. In a case where the power supply 201 fails, the power of the power supply 202 is supplied from the ECU 1306 to the ECU 1303 via the communication line 1313. Conversely, when the power supply 202 fails, the power of the power supply 201 is supplied from the ECU 1303 to the ECU 1306 via the communication line 1313.

Regarding power transmission between the ECU 1303 and the ECU 1305, the ECU 1303 and the ECU 1305 can supply power to each other by superimposing power via the communication line 1312. In a case where the power supply 201 fails, the power of the power supply 202 is supplied from the ECU 1303 to the ECU 1305 via the communication line 1312.

The ECU 1303 performs redundant communication with the ECU 1304 via the communication line 1311 and the communication line 1314, performs redundant communication with the ECU 1305 via the communication line 1312 and the communication line 1315, performs redundant communication with the ECU 1306 via the communication line 1313 and the communication line 1316, and exchanges data. Furthermore, the ECU 1303 supplies power to the sensor 231 via the power supply line 241, and performs control and data transmission/reception via the communication line 242. Further, the ECU 1303 supplies power to the actuator 232 via the power supply line 243, and performs control and data transmission/reception via the communication line 244.

The ECU 1304 performs redundant communication with the ECU 1303 via the communication line 1311 and the communication line 1314 to exchange data. Furthermore, the ECU 1304 supplies power to the sensor 233 via the power supply line 245, and performs control and data transmission/reception via the communication line 246. Further, the ECU 1304 supplies power to the actuator 234 via the power supply line 247, and performs control and data transmission/reception via the communication line 248.

The ECU 1305 performs redundant communication with the ECU 1303 via the communication line 1312 and the communication line 1315 to exchange data. Furthermore, the ECU 1305 supplies power to the sensor 235 via the power supply line 249, and performs control and data transmission/reception via the communication line 250. Further, the ECU 1305 supplies power to the actuator 236 via the power supply line 251, and performs control and data transmission/reception via the communication line 252.

The ECU 1306 performs redundant communication with the ECU 1303 via the communication line 1313 and the communication line 1316 to exchange data. Furthermore, the ECU 1306 supplies power to the sensor 237 via the power supply line 253, and performs control and data transmission/reception via the communication line 254. Further, the ECU 1306 supplies power to the actuator 238 via the power supply line 255, and performs control and data transmission/reception via the communication line 256.

[Configuration of Electronic Control Device]

Next, a configuration of an electronic control device (ECU) included in the power supply system 1300 will be described with reference to FIG. 14.

FIG. 14 is a block diagram illustrating a configuration example of an electronic control device (ECU 1303) included in the power supply system 1300. Configurations of the ECU 1304, the ECU 1305, and the ECU 1306 are substantially similar to those of the ECU 1303 except that the number of communication lines is reduced. Note that the number of power supply superimposition filters of the target ECU may be reduced according to the number of other ECUs connected to the target ECU through the communication lines. For example, in each of the ECU 1304, the ECU 1305, and the ECU 1306, one power supply superimposition filter may be provided.

The ECU 1303 includes an ECU core unit 1401, a power supply switcher 1402, a transceiver 1403, a power supply superimposition filter 1404, a power supply superimposition filter 1405, and a power supply superimposition filter 1406. A basic function of each processing block is similar to that of the ECU core unit 301, the power supply switcher 302, the transceiver 303, and the power supply superimposition filter 304 illustrated in FIG. 3.

The power supply superimposition filter 1404 is connected to the ECU 1304 via the communication line 1311, and exchanges a communication signal or a communication signal on which power is superimposed. In addition, the power supply superimposition filter 1404 is connected to the power supply switcher 1402 via a power supply line 1411 and is connected to the transceiver 1403 via a communication line 1421. In addition, the power supply superimposition filter 1404 is connected to the power supply superimposition filter 1405 and the power supply superimposition filter 1406 via the power supply line 1411. In the power supply superimposition filter 1404, only DC power and power having a frequency near DC pass between the communication line 1311 and the power supply line 1411, and only a high-frequency communication signal passes between the communication line 1311 and the communication line 1421.

The power supply superimposition filter 1405 is connected to the ECU 1305 via the communication line 1312, and exchanges a communication signal or a communication signal on which power is superimposed. In addition, the power supply superimposition filter 1405 is connected to the power supply switcher 1402 via the power supply line 1411 and is connected to the transceiver 1403 via a communication line 1422. In addition, the power supply superimposition filter 1405 is connected to the power supply superimposition filter 1404 and the power supply superimposition filter 1406 via the power supply line 1411. In the power supply superimposition filter 1405, only DC power and power having a frequency near DC pass between the communication line 1312 and the power supply line 1411, and only a high-frequency communication signal passes between the communication line 1312 and the communication line 1422.

The power supply superimposition filter 1406 is connected to the ECU 1306 via the communication line 1313, and exchanges a communication signal or a communication signal on which power is superimposed. In addition, the power supply superimposition filter 1406 is connected to the power supply switcher 1402 via the power supply line 1411 and is connected to the transceiver 1403 via a communication line 1423. In addition, the power supply superimposition filter 1406 is connected to the power supply superimposition filter 1404 and the power supply superimposition filter 1405 via the power supply line 1411. In the power supply superimposition filter 1406, only DC power and power having a frequency near DC pass between the communication line 1313 and the power supply line 1411, and only a high-frequency communication signal passes between the communication line 1313 and the communication line 1423.

The power supply switcher 1402 receives the power of the power supply 201 supplied via the power supply harness 207 and the power of the power supply 202 supplied via the power supply line 1411. Then, the power supply switcher 1402 internally monitors the voltage passing through the power supply harness 207 and the voltage passing through the power supply line 1411, and determines and switches which voltage is connected to the output. Accordingly, the power supply switcher 1402 supplies power to the ECU core unit 1401 via a power supply line 1413, to the transceiver 1403 via a power supply line 1412, to the sensor 231 via the power supply line 241, and to the actuator 232 via the power supply line 243.

In a case where the power supply 201 is normal, the power supply switcher 1402 supplies power from the power supply harness 207 to the ECU core unit 1401, the transceiver 1403, the sensor 231, and the actuator 232. On the other hand, in a case where the power supply 201 has failed and the power supply 202 is normal, the power supply switcher 1402 supplies the power transmitted through the power supply line 1411 to the ECU core unit 1401, the transceiver 1403, the sensor 231, and the actuator 232. In addition, since the power supply switcher 1402 can obtain the power supply failure information regarding the power supply 201, the power supply failure information can be transmitted to the ECU core unit 1401 via a communication line 1424 to share the power supply failure information with other ECUs.

The transceiver 1403 communicates with the ECU 1304 via the communication line 1311 via the communication line 1421 and the power supply superimposition filter 1404 and the communication line 1314. In addition, the transceiver 1403 communicates with the ECU 1305 via the communication line 1312 via the communication line 1422 and the power supply superimposition filter 1405 and the communication line 1315. In addition, the transceiver 1403 communicates with the ECU 1306 via the communication line 1313 via the communication line 1423 and the power supply superimposition filter 1406 and the communication line 1316. Then, the transceiver 1403 exchanges a transmission signal and a reception signal for another ECU with the ECU core unit 1401 via a communication line 1425.

The ECU core unit 1401 controls the transceiver 1403 via the communication line 1425, and exchanges data with the ECU 1304, the ECU 1305, and the ECU 1306 (FIG. 13) via the transceiver 1403. In addition, the ECU core unit 1401 performs control and data transmission/reception with respect to the sensor 231 and the actuator 232, and performs data processing.

As described above, according to the power supply system (power supply system 1300) according to the third embodiment, it is possible to reduce the number of communication lines as compared with the first embodiment since it is a star-type network in addition to effects similar to those of the first embodiment.

Fourth Embodiment

Next, a configuration of a power supply system according to a fourth embodiment of the present invention will be described with reference to FIG. 15.

[Configuration of Power Supply System]

FIG. 15 is a system configuration diagram illustrating an example of power supply redundancy of the power supply system according to the fourth embodiment. A power supply system 1500 illustrated in FIG. 15 uses a ring-type network architecture similarly to the power supply system 200 (FIG. 2) according to the first embodiment, and has a system in which the power supply harnesses are reduced as compared with the first embodiment, and power is supplied to the target ECU by power supply superimposition even when the power supply is normal.

The power supply 201 supplies power to an ECU 1503 via the power supply harness 207. In addition, the power supply 202 supplies power to an ECU 1504 via the power supply harness 211. That is, there is no power supply harness between the power supply 201 and an ECU 1505 and between the power supply 202 and an ECU 1506.

The ECU 1503 and the ECU 1504 can supply power to each other by superimposing power via the communication line 216. In a case where the power supply 201 fails, the power of the power supply 202 is supplied from the ECU 1504 to the ECU 1503 via the communication line 216. Conversely, when the power supply 202 fails, the power of the power supply 201 is supplied from the ECU 1503 to the ECU 1504 via the communication line 216.

The power of the ECU 1505 is supplied by superimposing the power of the power supply 201 via the ECU 1503 through the communication line 215. Similarly, the power of the ECU 1506 is supplied by superimposing the power of the power supply 202 via the ECU 1504 via the communication line 218.

The ECU 1505 and the ECU 1506 can supply power to each other by superimposing power via the communication line 217. In a case where the power supply 201 fails, the power of the power supply 202 is supplied to the ECU 1505 via the communication line 217 via the ECU 1504 and the ECU 1506. Conversely, when the power supply 202 fails, the power of the power supply 201 is supplied to the ECU 1506 via the communication line 217 via the ECU 1503 and the ECU 1505.

The ECU 1503 performs redundant communication with the ECU 1504 via the communication line 216 and the communication line 220, performs redundant communication with the ECU 1505 via the communication line 215 and the communication line 219, and exchanges data. Furthermore, the ECU 1503 supplies power to the sensor 231 via the power supply line 241, and performs control and data transmission/reception via the communication line 242. Further, the ECU 1503 supplies power to the actuator 232 via the power supply line 243, and performs control and data transmission/reception via the communication line 244.

The ECU 1504 performs redundant communication with the ECU 1503 via the communication line 216 and the communication line 220, performs redundant communication with the ECU 1506 via the communication line 218 and the communication line 222, and exchanges data. Furthermore, the ECU 1504 supplies power to the sensor 233 via the power supply line 245, and performs control and data transmission/reception via the communication line 246. Further, the ECU 1504 supplies power to the actuator 234 via the power supply line 247, and performs control and data transmission/reception via the communication line 248.

The ECU 1505 performs redundant communication with the ECU 1503 via the communication line 215 and the communication line 219, performs redundant communication with the ECU 1506 via the communication line 217 and the communication line 221, and exchanges data. Furthermore, the ECU 1505 supplies power to the sensor 235 via the power supply line 249, and performs control and data transmission/reception via the communication line 250. Further, the ECU 1505 supplies power to the actuator 236 via the power supply line 251, and performs control and data transmission/reception via the communication line 252.

The ECU 1506 performs redundant communication with the ECU 1504 via the communication line 218 and the communication line 222, performs redundant communication with the ECU 1505 via the communication line 217 and the communication line 221, and exchanges data. Furthermore, the ECU 1506 supplies power to the sensor 237 via the power supply line 253, and performs control and data transmission/reception via the communication line 254. Further, the ECU 1506 supplies power to the actuator 238 via the power supply line 255, and performs control and data transmission/reception via the communication line 256.

[Configuration of Electronic Control Device]

Next, a configuration of an electronic control device (ECU) included in the power supply system 1500 will be described with reference to FIG. 16.

FIG. 16 is a block diagram illustrating a configuration example of an electronic control device (ECU 1503) included in the power supply system 1500. The ECU 1504 has a configuration similar to the ECU 1503.

The ECU 1503 includes an ECU core unit 1601, a power supply switcher 1602, a transceiver 1603, a power supply superimposition filter 1604, and a power supply superimposition filter 1605. A basic function of each processing block is similar to that of the ECU core unit 301, the power supply switcher 302, the transceiver 303, and the power supply superimposition filter 304 illustrated in FIG. 3.

The power supply superimposition filter 1604 is connected to the ECU 1504 via the communication line 216, and exchanges a communication signal or a communication signal on which power is superimposed. In addition, the power supply superimposition filter 1604 is connected to the power supply switcher 1602 via a power supply line 1611 and is connected to the transceiver 1603 via a communication line 1621. In addition, the power supply superimposition filter 1604 is connected to the power supply superimposition filter 1605 via the power supply line