Power supply system and electronic control device

Abstract

To solve the problem that an electric power supply / communication network of redundant constitution increases in weight and cost as electric power supply harness increases.SOLUTION: A first switch circuit 401 cuts off supply of a first voltage to a first control circuit 301 when a drop in first voltage is equal to or larger than a threshold, a second switch circuit 402 cuts off supply of the first voltage to a communication line 216 when the drop in first voltage is equal to or larger than the threshold, and an electric power supply switch circuit 403 switches the supply source of a power supply voltage to the first control circuit 301 from a first power supply 201 to a second power supply 202.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a power supply system and an electronic control device using a technique of superimposing a power supply on a communication signal.

Background Art

[0002] In order to cope with the electrification and autonomous driving of automobiles, in-vehicle electronic control components such as sensors are increasing, and in-vehicle communication networks are becoming more complex. When the complexity of the in-vehicle communication network increases, there are concerns about cost increases due to an increase in the number of communication cables and cost increases due to an increase in assembly difficulty. Therefore, it has been proposed to shift the in-vehicle ECU (Electronic Control Unit) architecture from a domain type to a zone type. The zone architecture introduces high-speed communication and routing to simplify the in-vehicle communication network.

[0003] In addition, in autonomous driving, "Fail operational" (continuous operation during failure), which allows driving to continue even if one component breaks down, is required, so basically power supply and communication are made redundant. In the redundancy of the power supply, there is a system that has a main power supply and a sub-power supply and switches to the sub-power supply when the main power supply breaks down. One of the power supplies is not used all the time, and the power harness also needs to be doubled due to redundancy (see Patent Document 1).

[0004] The increase in the power harness leads to an increase in component cost, vehicle body weight, and assembly cost. A method of using a power supply used for another purpose as a redundant power supply is also conceivable, but the power supply voltages may be different from each other, and it is not possible to guarantee operations for both.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the technology described in Patent Document 1, due to power supply redundancy, an increase in power supply and an increase in power supply harness are expected, resulting in problems such as an increase in vehicle body weight, an increase in component costs, and an increase in assembly costs.

[0007] The present invention has been made in view of the above situation, and aims to reduce the power supply harness that increases with power supply redundancy in a system that performs power supply redundancy.

Means for Solving the Problems

[0008] To solve the above problems, a power supply system according to an aspect of the present invention includes a first control circuit, a first power supply that outputs a first voltage supplied as a power supply voltage to the first control circuit, a first switch circuit connected to the first power supply and the first control circuit for interrupting the power supply of the first voltage to the first control circuit, a second switch circuit connected to the communication line used for communication between the first power supply and the second control circuit for interrupting the supply of the first voltage to the communication line, a second power supply that outputs a second voltage supplied as a power supply voltage to the second control circuit, and a power supply switch circuit connected to the first control circuit and the communication line for supplying 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. 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 two-way power transmission using the communication line. The first switch circuit interrupts the supply of the first voltage to the first control circuit when the voltage drop of the first voltage is equal to or greater than a threshold value. The second switch circuit interrupts the supply of the first voltage to the communication line when the voltage drop of the first voltage is equal to or greater than a threshold value. The power supply switch circuit switches the power supply source of the power supply voltage to the first control circuit from the first power supply to the second power supply.

Advantages of the Invention

[0009] According to at least one aspect of the present invention, it is possible to achieve power redundancy without increasing the power harness. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0010]

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, examples of embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. In this specification and the accompanying drawings, the same components or components having substantially the same functions are denoted by the same reference numerals, and redundant descriptions are omitted.

[0012] <Conventional Power Supply System> Before explaining the power supply system according to the embodiment of the present invention, an example of power redundancy of a conventional power supply system will be described with reference to FIG. 1.

[0013] FIG. 1 is a system configuration diagram showing an example of power redundancy of a conventional power supply system. The power supply system 100 shown in FIG. 1 has a configuration in which ECUs 103 to 106 are connected in a ring between in a zone architecture, and is an example in which power and communication are made redundant without using a power overlay technique. Power supply 101 and power supply 102 are redundant power supplies, and power (electric power) is supplied from power supply 102 to ECUs 103 to 106 only when power supply 101 fails.

[0014] Power supply 101 supplies power to ECU 103 via power harness 107 and to ECU 105 via power harness 108. Further, power supply 101 supplies power from ECU 103 to ECU 104 via power harness 109 and from ECU 105 to ECU 106 via power harness 110.

[0015] When power supply 101 fails, power supply 102 supplies power to ECU 104 via power harness 111 and to ECU 106 via power harness 112. Further, power supply 102 supplies power from ECU 104 to ECU 103 via power harness 113 and from ECU 106 to ECU 105 via power harness 114.

[0016] ECUs 103 to 106 are interconnected by redundant communication lines, and communication is also made redundant. ECU 103 and ECU 104 communicate via communication line 116 and communication line 120. ECU 103 and ECU 105 communicate via communication line 115 and communication line 119. ECU 104 and ECU 106 communicate via communication line 118 and communication line 122. ECU 105 and ECU 106 communicate via communication line 117 and communication line 121.

[0017] ECU 103 supplies power to sensor 131 via power line 141, and performs control and data exchange with sensor 131 via communication line 142. Further, ECU 103 supplies power to actuator 132 via power line 143, and performs control and data exchange with actuator 132 via communication line 144.

[0018] The ECU 104 supplies power to the sensor 133 via the power line 145, and performs control and data transfer with the sensor 133 via the communication line 146. Further, the ECU 104 supplies power to the actuator 134 via the power line 147, and performs control and data transfer with the actuator 134 via the communication line 148.

[0019] The ECU 105 supplies power to the sensor 135 via the power line 149, and performs control and data transfer with the sensor 135 via the communication line 150. Further, the ECU 105 supplies power to the actuator 136 via the power line 151, and performs control and data transfer with the actuator 136 via the communication line 152.

[0020] The ECU 106 supplies power to the sensor 137 via the power line 153, and performs control and data transfer with the sensor 137 via the communication line 154. Further, the ECU 106 supplies power to the actuator 138 via the power line 155, and performs control and data transfer with the actuator 138 via the communication line 156.

[0021] <First Embodiment> Next, the configuration of the power supply system according to the first embodiment of the present invention will be described with reference to FIG. 2. In the present invention, for example, in an ECU used in a zone architecture, by using a power superposition technique to make the power redundant by a communication line, it is possible to make the power redundant without increasing the power harness. Since the communication lines connect all the ECUs, each power source connects the power harness under the jurisdiction of some ECUs, and when a failure occurs, power supply from a power source not directly connected to the ECU by the power harness is performed using the communication line. When each power source fails, it switches to power supply from the communication line. However, since which power source supplies power changes depending on the failed power source, a power switch capable of bidirectional power supply is used to perform power redundancy by the communication line.

[0022] [Configuration of Power Supply System] FIG. 2 is a system configuration diagram showing an example of power redundancy of the power supply system according to the first embodiment. The power supply system 200 shown in FIG. 2 is an example in which power redundancy is performed via a communication line using a power superposition technique, and the power harness is reduced. In the present embodiment, a ring-type network architecture is used for the power supply system 200. In the power supply system 200, the power harnesses 109 and 113 corresponding to between the ECUs 203 and 204 and the power harnesses 110 and 114 corresponding to between the ECUs 105 and 106 are reduced from the power supply system 100 of FIG. 1. Instead, power superposition for transmitting power and communication is performed on the communication line 216 connecting between the ECUs 203 and 204 and the communication line 217 connecting between the ECUs 205 and 206 to realize power redundancy.

[0023] The power supply system 200 includes a power source 201, a power source 202, ECUs 203, 204, 205, 206, power harnesses 207 to 208, power harnesses 211 to 212, communication lines 215 to 218 shown by solid lines, and communication lines 219 to 222 shown by broken lines. The communication lines 215 to 218 shown by solid lines are communication lines for power superposition. The communication lines 219 to 222 shown by broken lines are communication lines for communication. However, the same communication lines for power superposition as the communication lines 215 to 218 may be used for the communication lines 219 to 222.

[0024] The power source 201 supplies power to the ECU 203 via the power harness 207 and to the ECU 205 via the power harness 208. The power source 202 supplies power to the ECU 204 via the power harness 211 and to the ECU 206 via the power harness 212.

[0025] The ECUs 203 and 204 can supply power to each other by power superposition via the communication line 216. If the power source 201 fails, the power of the power source 202 is supplied from the ECU 204 to the ECU 203 via the communication line 216. Conversely, when the power source 202 fails, the power of the power source 201 is supplied from the ECU 203 to the ECU 204 via the communication line 216.

[0026] Also, the power transmission between ECU205 and ECU206 is the same. ECU205 and ECU206 can supply power to each other through power superposition via communication line 217. If power supply 201 fails, the power of power supply 202 is supplied from ECU206 to ECU205 via communication line 217. Conversely, when power supply 202 fails, the power of power supply 201 is supplied from ECU205 to ECU206 via communication line 217.

[0027] ECU203 performs redundant communication with ECU204 via communication lines 216 and 220, performs redundant communication with ECU205 via communication lines 215 and 219, and exchanges data. Also, ECU203 supplies power to sensor 231 via power line 241 and performs control and data exchange via communication line 242. Furthermore, ECU203 supplies power to actuator 232 via power line 243 and performs control and data exchange via communication line 244.

[0028] ECU204 performs redundant communication with ECU203 via communication lines 216 and 220, performs redundant communication with ECU206 via communication lines 218 and 222, and exchanges data. Also, ECU204 supplies power to sensor 233 via power line 245 and performs control and data exchange via communication line 246. Furthermore, ECU204 supplies power to actuator 234 via power line 247 and performs control and data exchange via communication line 248.

[0029] ECU205 performs redundant communication with ECU203 via communication line 215 and communication line 219, performs redundant communication with ECU206 via communication line 217 and communication line 221, and exchanges data. Also, ECU205 supplies power to sensor 235 via power line 249 and performs control and data exchange via communication line 250. Further, ECU205 supplies power to actuator 236 via power line 251 and performs control and data exchange via communication line 252.

[0030] ECU206 performs redundant communication with ECU204 via communication line 218 and communication line 222, performs redundant communication with ECU205 via communication line 217 and communication line 221, and exchanges data. Also, ECU206 supplies power to sensor 237 via power line 253 and performs control and data exchange via communication line 254. Further, ECU206 supplies power to actuator 238 via power line 255 and performs control and data exchange via communication line 256.

[0031] Here, an example where one sensor and one actuator are connected to each of the ECUs 203 to 206 is shown, but the number of sensors and actuators is not limited to one. Even if the number of sensors and actuators increases or decreases, the power redundancy configuration of the power supply system 200 remains the same.

[0032] [Configuration of Electronic Control Unit] Next, the configuration of the electronic control unit (ECU) included in the power supply system 200 will be described with reference to FIG. 3.

[0033] FIG. 3 is a block diagram showing a configuration example of the electronic control unit (ECU203) included in the power supply system 200. The ECUs 204, 205, and 206 have the same configuration as ECU203. ECU203 includes an ECU core unit 301 that performs control and information processing, a power switch 302, a transceiver 303, and a power superimposition filter 304.

[0034] The power superimposition filter 304 is connected to the ECU 204 via the communication line 216, and exchanges communication signals or communication signals with power superimposed thereon. The power superimposition filter 304 is also connected to the power switch 302 via the power line 305 and connected to the transceiver 303 via the communication line 308. In the power superimposition filter 304, only DC (Direct Current) power and power having a frequency near DC can pass between the communication line 216 and the power line 305, and only high-frequency communication signals can pass between the communication line 216 and the communication line 308. The power superimposition filter 304 is configured using, for example, PoDL (Power over DataLines) to separate and superimpose communication signals and power. In PoDL, DC (Direct Current) power is superimposed on a signal (differential) and transmitted using a pair of twisted cables.

[0035] The power switch 302 receives the power of the power supply 201 supplied via the power harness 207 and the power of the power supply 202 supplied via the power line 305. Then, inside the power switch 302, the voltage passing through the power harness 207 and the voltage passing through the power line 305 are monitored, and it is determined which voltage to connect to the output and switched. Thereby, the power switch 302 supplies power to the ECU core unit 301 via the power line 307, to the transceiver 303 via the power line 306, to the sensor 231 via the power line 241, and to the actuator 232 via the power line 243, respectively.

[0036] When the power supply 201 is normal, the power switch 302 supplies the power from the power harness 207 to the ECU core unit 301, the transceiver 303, the sensor 231, and the actuator 232. On the other hand, when the power supply 201 fails and the power supply 202 is normal, the power switch 302 supplies the power transmitted through the power line 305 to the ECU core unit 301, the transceiver 303, the sensor 231, and the actuator 232. In addition, since the power switch 302 can obtain information indicating that the power supply 201 has failed (power failure information), it can send the power failure information to the ECU core unit 301 via the communication line 309 to share the power failure information with other ECUs.

[0037] In this way, when the power supply of the first voltage of the first power supply (power supply 201) to the first control circuit (ECU core unit 301) is cut off, the first control circuit notifies an external device (for example, another ECU) that the first power supply is abnormal. As a result, for example, other in-vehicle ECUs can perform appropriate control such as continuous driving control in response to the abnormality of the first power supply.

[0038] The transceiver 303 communicates with the ECU 204 via the communication line 216 passing through the communication line 308 and the power supply superimposition filter 304 and the communication line 220. Further, the transceiver 303 communicates with the ECU 205 via the communication line 215 and the communication line 219. Then, the transceiver 303 exchanges transmission signals and reception signals for other ECUs with the ECU core unit 301 via the communication line 310.

[0039] The ECU core unit 301 controls the transceiver 303 through 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 the other ECU 204 or via the ECU 204 by designating each other as the transmission source and the transmission destination by routing. Further, the ECU core unit 301 performs control and data exchange with the sensor 231 and the actuator 232, and processes data.

[0040] For example, in addition to a processor (not shown), the ECU core unit 301 may have a memory (ROM, RAM) and a non-volatile storage. For example, a processor such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit) can be used as the processor of the ECU core unit 301. When the processor executes a computer program stored in the ROM or the non-volatile storage, the functions of the ECU core unit in the embodiment of the present invention are realized.

[0041] [Configuration of Power Switcher] Next, the configuration of the power switch included in the electronic control unit (ECU) according to this embodiment will be described with reference to FIG. 4.

[0042] FIG. 4 is a block diagram showing a configuration example of the power switch 302 included in the ECU 203. The power switch 302 includes a self-power switch 401, an other-load switch 402, an other-power switch 403, and a power circuit 404. The solid lines without arrows connecting the self-power switch 401, the other-load switch 402, and the other-power switch 403 represent the power usage of the power, and the solid lines with arrows represent the control usage of the power.

[0043] The self-power switch 401 monitors the voltage of the power harness 207. If the voltage is equal to or higher than a preset threshold voltage, it turns on the internal switch, conducts the power harness 207 and the power line 405, and supplies power to the power circuit 404 through the power line 405. If the voltage of the power harness 207 is lower than the threshold voltage, the self-power switch 401 turns off the internal switch and cuts off the connection between the power harness 207 and the power line 405. Also, the self-power switch 401 outputs a signal based on the comparison result between the voltage from the power harness 207 and the threshold voltage to the ECU core unit 301 via the communication line 309. This signal corresponds to the power failure information described in FIG. 3.

[0044] The other-load switch 402 monitors the voltages of the power harness 207 and the power line 305. If both voltages are equal to or higher than a preset threshold voltage, it turns on the internal switch and conducts the power harness 207 and the power line 305. When either the voltage of the power harness 207 or the voltage of the power line 305 is lower than the threshold voltage, the other-load switch 402 turns off the internal switch and cuts off the connection between the power harness 207 and the power line 305.

[0045] The other power switch 403 monitors the voltage of the power harness 207. When the voltage is equal to or higher than a preset threshold voltage, it turns off the internal switch, cuts off the power line 305 and the power line 405, and does not supply power to the power circuit 404. When the voltage of the power harness 207 drops below the threshold voltage, the other power switch 403 conducts between the power line 305 and the power line 405 and supplies power to the power circuit 404 through the power line 405.

[0046] The power circuit 404 converts the voltage of the power transmitted from the power line 405 according to the supply destination and supplies power through the power lines 306, 307, 241, and 243 respectively.

[0047] [First Example of Each Switch] Here, a first example of the self-power switch, the other load switch, and the other power switch that constitute the power switch 302 in this embodiment will be described with reference to FIG. 5.

[0048] FIG. 5 is a circuit diagram showing a first example of the self-power switch 401, the other load switch 402, and the other power switch 403 that constitute the power switch 302. The self-power switch 401 is composed of a MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) 501, a comparator 502, and a threshold voltage source 503.

[0049] The MOSFET 501 shows an example of a P-type MOSFET. In the high-voltage type, a diode is connected between the drain and the source. The same applies to the MOSFETs used in the following switches.

[0050] Comparator 502 compares the voltage from power harness 207 with the threshold voltage of threshold voltage source 503. If the voltage from power harness 207 is equal to or higher than the threshold voltage, it outputs a Low level, turns on MOSFET 501, and conducts power harness 207 and power line 405. On the other hand, if the voltage from power harness 207 is lower than the threshold voltage, comparator 502 outputs a High level, turns off MOSFET 501, and cuts off the connection between power harness 207 and power line 405. The output of comparator 502 is transmitted to ECU core unit 301 via communication line 309.

[0051] Another load switch 402 is composed of MOSFET 504, OR circuit 505, comparator 506, threshold voltage source 507, comparator 508, and threshold voltage source 509. Comparator 506 compares the voltage of power supply 201 from power harness 207 with the threshold voltage of threshold voltage source 507. If the voltage from power harness 207 is equal to or higher than the threshold voltage, it outputs a Low level; conversely, if the voltage from power harness 207 is lower than the threshold voltage, it outputs a High level.

[0052] Comparator 508 compares the voltage of power supply 202 from power line 305 with the threshold voltage of threshold voltage source 509. If the voltage from power line 305 is equal to or higher than the threshold voltage, it outputs a Low level; conversely, if the voltage from power line 305 is lower than the threshold voltage, it outputs a High level.

[0053] OR circuit 505 is a logical OR circuit that outputs a High level if either the output voltage of comparator 506 or the output voltage of comparator 508 is High, and outputs a Low level if both output voltages are Low.

[0054] MOSFET 504 turns on if the output of OR circuit 505 is Low, and conducts power harness 207 and power line 305. On the other hand, MOSFET 504 turns off if the output of OR circuit 505 is High, and cuts off the connection between power harness 207 and power line 305.

[0055] The other power switch 403 is composed of only the MOSFET 510. Of course, similar to the self-power switch 401, a comparator may be used for the other power switch 403. The MOSFET 510 turns on only when the voltage of the power harness 207 is lower than the voltage required to switch the MOSFET 510 with respect to the voltage of the power line 405 (the source-gate voltage is smaller than the threshold voltage), and the power line 405 and the power line 305 are electrically connected.

[0056] In the initial state, since the voltage of the power line 405 starts in a low state, the MOSFET 501 and the MOSFET 510 are turned off. For example, the initial state is when the power is turned on, when the ECU 203 is started, when the vehicle is started, and so on. Here, since a diode is connected between the drain and the source of the MOSFET 501, if the voltage of the power harness 207 becomes higher than the threshold voltage of the diode, the power line 405 and the power harness 207 are electrically connected, and the value of the voltage of the power line 405 increases, so the MOSFET 501 also turns on. Similarly, when the voltage of the power line 305 starts in a low state, the MOSFET 504 is initially turned off, but the power harness 207 and the power line 305 are electrically connected through the diode connected between the drain and the source of the MOSFET 504, the value of the voltage of the power line 305 increases, and the MOSFET 504 also turns on.

[0057] According to the power switch with the above configuration, the power through the power harness and the power through the communication line can be switched quickly and with low loss in the event of a power failure.

[0058] [Second Example of Each Switch] Next, a second example of the self-power switch, the other-load switch, and the other-power switch that constitute the power switch 302 in the present embodiment will be described with reference to FIG. 6.

[0059] FIG. 6 is a circuit diagram showing a second example of the self-power switch 401A, the other-load switch 402A, and the other-power switch 403 that constitute the power switch 302. The configuration of the power switch 302 shown in FIG. 6 is different from that of the power switch 302 of the first example shown in FIG. 5 in that a level shifter (denoted as "LV" in the figure) is used instead of the threshold voltage source, and its operation is substantially the same as that of the first example.

[0060] The self-power switch 401A is composed of a MOSFET 501, a comparator 502, and a level shifter 601. The level shifter 601 shifts the voltage from the power harness 207 by a preset voltage and outputs it to the comparator 502. The comparator 502 outputs a Low level if the output voltage of the level shifter 601 is positive and a High level if it is negative, thereby controlling the ON / OFF of the MOSFET 501. At this time, the output of the comparator 502 is transmitted to the ECU core unit 301 via the communication line 309.

[0061] The other-load switch 402A is composed of 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 harness 207 by a preset voltage and outputs it to the comparator 506. The comparator 506 outputs a Low level if the output voltage of the level shifter 602 is positive and a High level if it is negative. The level shifter 603 shifts the voltage from the power line 305 by a preset voltage and outputs it to the comparator 508. The comparator 508 outputs a Low level if the output voltage of the level shifter 603 is positive and a High level if it is negative.

[0062] The OR circuit 505 controls the ON / OFF of the MOSFET 504 by setting the output to High level if either the output voltage of the comparator 506 or the output voltage of the comparator 508 is High level, and setting the output to Low level if both output voltages are Low level.

[0063] [Third Example of Each Switch] Next, a third example of the self-power switch, other-load switch, and other-power switch that constitute the power switch 302 in the present embodiment will be described with reference to FIG. 7.

[0064] FIG. 7 is a circuit diagram showing a third example of the self-power switch 401B, other-load switch 402B, and other-power switch 403B that constitute the power switch 302. The configuration of the power switch 302 shown in FIG. 7 is different from that of the power switch 302 in the first example shown in FIG. 5 in that countermeasures against current leakage due to a ground fault are taken for the power line 405, the power line 305, and their connection destinations in each switch.

[0065] A P-type MOSFET 701 with the drain-source direction opposite to that of the MOSFET 501 is added to the self-power 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.

[0066] Also, an MOSFET 702 with the 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. And the source of the MOSFET 701 of the self-power switch 401B and the source of the MOSFET 702 of the other-load switch 402B are connected. Also, each source of the MOSFET 701 and the MOSFET 702 is connected to the power harness 207.

[0067] Furthermore, an MOSFET 703 with the drain-source direction opposite to that of the MOSFET 510 is added to the other-power 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 line 305, and the gate of the MOSFET 703 is connected to the power harness 207.

[0068] MOSFET701, MOSFET702, and MOSFET703 all have the opposite diode orientation compared to the original MOSFET501, MOSFET504, and MOSFET510. The diodes of these MOSFET701 - 703 can prevent the occurrence of current leakage.

[0069] Thus, in the power switch (power switch 302) according to this embodiment, when the voltage drop of the first voltage (the voltage of power supply 201) is smaller than the threshold value, the first switch circuit (self - power switch 401B) includes a first switching element (MOSFET501) that energizes between the first power supply (power supply 201) and the first control circuit (ECU core unit 301), and a switching element (MOSFET701) connected in series with and having the opposite polarity to the first switching element between the first power supply and the first control circuit. Also, when the voltage drops of both the first voltage and the second voltage (the voltage of power supply 202) are smaller than the threshold value, the second switch circuit (other - load switch 402B) includes a second switching element (MOSFET504) that energizes between the first power supply and the communication line (communication line 216 (power line 305)), and a switching element (MOSFET702) connected in series with and having the opposite polarity to the second switching element between the first power supply and the communication line. Further, when the voltage drop of the first voltage is smaller than the threshold value, the power - switch circuit (other - power - supply switch 403B) includes a third switching element (MOSFET510) that energizes between the first control circuit and the communication line (communication line 216 (power line 305)), and a switching element (MOSFET703) connected in series with and having the opposite polarity to the third switching element between the first control circuit and the communication line.

[0070] [Fourth Example of Each Switch] Next, a fourth example of the self - power switch, other - load switch, and other - power - supply switch that constitute the power switch 302 in this embodiment will be described with reference to FIG. 8.

[0071] FIG. 8 is a circuit diagram showing a fourth example of the self-power switch 401C, the other-load switch 402C, and the other-power switch 403B that constitute the power switch 302. The configuration of the power switch 302 shown in FIG. 8 is different from that of the power switch 302 of the second example shown in FIG. 6 in that countermeasures are taken for each switch so that current leakage does not occur between the power line 405, the power line 305, and their connection destinations due to a ground fault. That is, the fourth example of the power switch 302 has the same measures as those of the third example.

[0072] In the self-power switch 401C, a MOSFET 701 with the drain-source direction opposite to that of the MOSFET 501 is added between the drain of the MOSFET 501 and the power harness 207, and the gate of the MOSFET 701 is connected to the output terminal of the comparator 502.

[0073] In the other-load switch 402C, a MOSFET 702 with the drain-source direction opposite to that of the MOSFET 504 is added between the drain of the MOSFET 504 and the power harness 207, and the gate of the MOSFET 702 is connected to the output terminal of the OR circuit 505.

[0074] Similar to the third example of the power switch 302 shown in FIG. 7, the diodes of the MOSFETs 701, 702, and 703 are all in the opposite direction to those of the original MOSFETs 501, 504, and 510. The diodes of these MOSFETs 701 to 703 can prevent the occurrence of current leakage.

[0075] Note that N-type MOSFETs may be used for the MOSFETs of each of the above-described switches to configure the circuits of the switches of the power switch 302. Also, other switching elements may be used instead of the MOSFETs. Hereinafter, in this specification, when the self-power switches 401 to 401C are not distinguished or collectively referred to, they may simply be described as "self-power switch 401". Similarly, the other-load switches 402 to 402C may be described as "other-load switch 402", and the other-power switches 403, 403B may be described as "other-power switch 403".

[0076] As described above, in the power supply system (power supply system 200 (ECU 203)) according to the first embodiment, a first control circuit (ECU core unit 301), a first power supply (power supply 201) that outputs a first voltage supplied as a power supply voltage to the first control circuit, a first power supply (power harness 207) and a first switch circuit (self-power switch 401 to 401C) connected to the first control circuit, which cuts off the power supply of the first voltage to the first control circuit, and a communication line (for example, communication line 216) used for communication between the first power supply and the second control circuit, and a second switch circuit (other load switch 402 to 402C) that cuts off the supply of the first voltage to the communication line, a second power supply (power supply 202) that outputs a second voltage supplied as a power supply voltage to the second control circuit, and a power supply switch circuit (other power supply switch 403, 403B) that 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 cut off by the first switch circuit. Here, the power supply to the second control circuit of the first voltage and the power supply to the first control circuit of the second voltage are two-way power transmission using the communication line. When the voltage drop of the first voltage is equal to or greater than the threshold value, the first switch circuit cuts off the supply of the first voltage to the first control circuit. When the voltage drop of the first voltage is equal to or greater than the threshold value, the second switch circuit cuts off the supply of the first voltage to the communication line. The power supply switch circuit switches the power supply source of the power supply voltage to the first control circuit from the first power supply to the second power supply.

[0077] According to the present embodiment having the above configuration, by using the power redundancy technology and two-way power transmission, the power supply source can be switched from the first power supply to the second power supply, so that power redundancy can be realized without increasing the power harness as in the prior art.

[0078] Also, in the power supply system (power supply system 200 (ECU 203)) according to the present embodiment, the first switch circuit (self-power switch 401 to 401C) has a voltage drop of the first voltage smaller than the threshold valueCase Supply a first voltage to the first control circuit. The second switch circuit (other load switches 402 to 402C) supplies the first voltage to the communication line when the voltage drop of the first voltage is smaller than the threshold value and the voltage drop of the second voltage is equal to or greater than the threshold value. The power supply switch circuit (other power supply switches 403, 403B) disconnects the first control circuit from the communication line.

[0079] According to the present embodiment having the above configuration, by using a power supply redundancy technique and performing bidirectional power transmission, when there is an abnormality in the second voltage of the second power supply, the first voltage can be supplied to the second control circuit. Therefore, power supply redundancy can be achieved without increasing the power supply harness.

[0080] <Second Embodiment> Next, the configuration of the power supply switch included in the electronic control unit (ECU) according to the second embodiment of the present invention will be described with reference to FIG. 9.

[0081] [Configuration of Power Supply Switch] FIG. 9 is a block diagram showing a configuration example of a power supply switch 302A included in the ECU 203. The configuration of the power supply switch 302A shown in FIG. 9 is different from that of the power supply switch 302 shown in FIG. 4 in that the determination control circuits (comparators, OR circuits, etc. in FIGS. 5 to 8) provided in each of the self-power supply switch 401, the other load switch 402, and the other power supply switch 403 are combined into one controller 907.

[0082] The power supply switch 302A includes a self-power supply switch 901, an other load switch 902, an other power supply switch 903, a controller 907, and a power supply circuit 404.

[0083] All of the self-power supply switch 901, the other load switch 902, and the other power supply switch 903 are configured by using one MOSFET or two MOSFETs as shown in FIGS. 5 to 8. The self-power supply switch 901, the other load switch 902, and the other power supply switch 903 have the same switching function as the self-power supply switch 401, the other load switch 402, and the other power supply switch 403 shown in FIG. 4.

[0084] The controller 907 receives the voltage from the power harness 207 and the voltage from the power line 305. Then, according to the voltages of the power harness 207 and the power line 305, the controller 907 controls the self-power switch 901 via the communication line 309, controls the other-load switch 902 via the control line 905, and controls the other-power switch 903 via the control line 906.

[0085] In the self-power switch 901 composed of one or two MOSFETs, the gate of each MOSFET receives a control signal from the controller 907 via the communication line 309. Also, in the other-load switch 902 composed of one or two MOSFETs, the gate of each MOSFET receives a control signal from the controller 907 via the control line 905. Further, in the other-power switch 903 composed of one or two MOSFETs, the gate of each MOSFET receives a control signal from the controller 907 via the control line 906.

[0086] [First Example of Controller] Here, a first example of the controller 907 that constitutes the power switch 302A in the present embodiment will be described with reference to FIG. 10.

[0087] FIG. 10 is a circuit diagram showing a first example of the controller 907 that constitutes the power switch 302A. The controller 907 is composed of 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.

[0088] The comparator 1001 compares the voltage from the power harness 207 with the threshold voltage of the threshold voltage source 1002. If the voltage from the power harness 207 is equal to or higher than the threshold voltage, the output is at the Low level; conversely, if the voltage from the power harness 207 is lower than the threshold voltage, the output is at the High level. The comparator 1001 outputs a signal corresponding to the comparison result to the communication line 309.

[0089] Comparator 1003 compares the voltage from power line 305 with the threshold voltage of threshold voltage source 1004. If the voltage from power line 305 is equal to or higher than the threshold voltage, the output is at the Low level; conversely, if the voltage from power line 305 is lower than the threshold voltage, the output is at the High level.

[0090] OR circuit 1005 outputs a High level if either the output voltage of comparator 1001 or the output voltage of comparator 1003 is at the High level, and outputs a Low level if both output voltages are at the Low level. OR circuit 1005 outputs a signal according to the logical operation result to control line 905 connected to other load switch 902.

[0091] NOT circuit 1006 inverts the output value of comparator 1001 and outputs it to control line 906 connected to other power switch 903. NOT circuit 1006 outputs a High level when the output voltage of comparator 1001 is at the Low level, and outputs a Low level when the output voltage of comparator 1001 is at the High level.

[0092] [Second example of the controller] Next, a second example of controller 907A that constitutes power switch 302A in this embodiment will be described with reference to FIG. 11.

[0093] FIG. 11 is a circuit diagram showing a second example of controller 907A that constitutes power switch 302A. The configuration of controller 907A shown in FIG. 11 differs from that of controller 907 in the first example shown in FIG. 10 in that a level shifter (denoted as "LV" in the figure) is used instead of the threshold voltage source, and the operation is substantially the same as that of the first example.

[0094] Controller 907A is composed of comparator 1001, level shifter 1101, comparator 1003, level shifter 1102, OR circuit 1005, and NOT circuit 1006.

[0095] The level shifter 1101 shifts the voltage from the power harness 207 by a preset voltage and outputs it to the comparator 1001. When the output voltage of the level shifter 1101 is positive, the comparator 1001 outputs a Low level, and when it is negative, it outputs a High level.

[0096] The level shifter 1102 shifts the voltage from the power line 305 by a preset voltage and outputs it to the comparator 1003. When the output voltage of the level shifter 1102 is positive, the comparator 1003 outputs a Low level, and when it is negative, it outputs a High level.

[0097] The OR circuit 1005 outputs a High level if either of the output voltages of the comparator 1001 and the comparator 1003 is High, and outputs a Low level if both output voltages are Low. The NOT circuit 1006 inverts the output value of the comparator 1001. The NOT circuit 1006 outputs a High level when the input is Low and outputs a Low level when the input is High.

[0098] [Third Example of the Controller] Next, a third example of the controller 907B that constitutes the power switch 302A in the present embodiment will be described with reference to FIG. 12.

[0099] FIG. 12 is a circuit diagram showing a third example of the controller 907B that constitutes the power switch 302A. The controller 907B is composed of an ADC (Analog-to-Digital Converter) 1201, an ADC 1202, and a microprocessor (denoted as "MCU" in the figure) 1203. For example, an MCU (Micro Controller Unit) can be used for the microprocessor 1203. Generally, an MCU includes a processor, a memory such as a ROM and a RAM, and I / O. Since the controller 907B in the present embodiment can convert the voltages (analog signals) from the power harness 207 and the power line 305 into digital data, the control content can be modified by programming.

[0100] The ADC1201 converts the voltage value from the power harness 207 into a digital value and outputs the digital value to the microprocessor 1203. Also, the ADC1202 converts the voltage value from the power line 305 into a digital value and outputs the digital value to the microprocessor 1203.

[0101] The microprocessor 1203 receives the outputs of the ADC1201 and the ADC1202. If the output code (digital value of the voltage) of the ADC1201 is greater 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 switch 903 to the High level. Also, 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. Further, if either the output code of the ADC1201 or the output code of the ADC1202 is greater than their respective set codes, 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.

[0102] As described above, in the power switch (power switch 302A) of the power supply system (power supply system 200) according to the second embodiment, the determination control circuits (comparators, OR circuits, etc. 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 this embodiment, the configuration of each switch circuit constituting the power switch can be simplified.

[0103] <The Third Embodiment> Next, the configuration of the power supply system according to the third embodiment of the present invention will be described with reference to FIG. 13.

[0104] [Configuration of Power Supply System] FIG. 13 is a system configuration diagram showing an example of power redundancy of a power supply system according to the third embodiment. The power supply system 200 (FIG. 2) according to the first and second embodiments had a ring architecture using four ECUs 203 to 206, but the power supply system 1300 according to this embodiment has a star architecture using four ECUs 1303 to 1306. Here, an example with four ECUs is shown, but the basic connection method does not change even if the number of ECUs increases. In this architecture, the central ECU (ECU1303) and the other ECUs (ECU1304 to 1306) are connected by communication lines. The advantage of the star architecture is that the number of communication lines can be reduced.

[0105] 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 harnesses 207 to 208, power harnesses 211 to 212, communication lines 1311 to 1313 shown by solid lines, and communication lines 1314 to 1316 shown by broken lines. The communication lines 1311 to 1313 shown by solid lines are communication lines for power superposition. Also, the communication lines 1314 to 1316 shown by broken lines are communication lines for communication. However, the same communication lines for power superposition as the communication lines 1311 to 1313 may be used for the communication lines 1314 to 1316.

[0106] The power supply 201 supplies power to the ECU 1303 via the power harness 207 and to the ECU 1305 via the power harness 208. Also, the power supply 202 supplies power to the ECU 1304 via the power harness 211 and to the ECU 1306 via the power harness 212.

[0107] The ECU 1303 and the ECU 1304 can supply power to each other by power superposition via the communication line 1311. If 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.

[0108] Also, the power transmission between ECU1303 and ECU1306 is the same. ECU1303 and ECU1306 can supply power to each other through power superposition via communication line 1313. If power supply 201 fails, the power of power supply 202 is supplied from ECU1306 to ECU1303 via communication line 1313. Conversely, when power supply 202 fails, the power of power supply 201 is supplied from ECU1303 to ECU1306 via communication line 1313. Regarding the power transmission between ECU1303 and ECU1305, ECU1303 and ECU1305 can supply power to each other through power superposition via communication line 1312. If power supply 201 fails, the power of power supply 202 is supplied from ECU1303 to ECU1305 via communication line 1312.

[0109] ECU1303 performs redundant communication with ECU1304 via communication lines 1311 and 1314, performs redundant communication with ECU1305 via communication lines 1312 and 1315, performs redundant communication with ECU1306 via communication lines 1313 and 1316, and exchanges data. Also, ECU1303 supplies power to sensor 231 via power line 241 and performs control and data exchange via communication line 242. Furthermore, ECU1303 supplies power to actuator 232 via power line 243 and performs control and data exchange via communication line 244.

[0110] ECU1304 performs redundant communication with ECU1303 via communication lines 1311 and 1314 and exchanges data. Also, ECU1304 supplies power to sensor 233 via power line 245 and performs control and data exchange via communication line 246. Furthermore, ECU1304 supplies power to actuator 234 via power line 247 and performs control and data exchange via communication line 248.

[0111] ECU 1305 performs redundant communication with ECU 1303 via communication lines 1312 and 1315, and exchanges data. Also, ECU 1305 supplies power to sensor 235 via power line 249 and performs control and data exchange via communication line 250. Further, ECU 1305 supplies power to actuator 236 via power line 251 and performs control and data exchange via communication line 252.

[0112] ECU 1306 performs redundant communication with ECU 1303 via communication lines 1313 and 1316, and exchanges data. Also, ECU 1306 supplies power to sensor 237 via power line 253 and performs control and data exchange via communication line 254. Further, ECU 1306 supplies power to actuator 238 via power line 255 and performs control and data exchange via communication line 256.

[0113] [Configuration of Electronic Control Unit] Next, the configuration of the electronic control unit (ECU) included in the power supply system 1300 will be described with reference to FIG. 14.

[0114] FIG. 14 is a block diagram showing a configuration example of the electronic control unit (ECU 1303) included in the power supply system 1300. The configurations of ECU 1304, ECU 1305, and ECU 1306 are substantially the same as that of ECU 1303 except that the communication lines are reduced. Note that the number of power superposition filters of the target ECU may be reduced according to the number of other ECUs connected to the target ECU via communication lines. For example, in each of ECU 1304, ECU 1305, and ECU 1306, one power superposition filter may be provided.

[0115] ECU 1303 is composed of an ECU core unit 1401, a power switch 1402, a transceiver 1403, power superposition filters 1404, 1405, and 1406. The basic functions of each processing block are the same as those of the ECU core unit 301, power switch 302, transceiver 303, and power superposition filter 304 shown in FIG. 3.

[0116] The power superimposition filter 1404 is connected to the ECU 1304 via the communication line 1311, and exchanges communication signals with or without superimposed power. The power superimposition filter 1404 is also connected to the power switch 1402 via the power line 1411 and to the transceiver 1403 via the communication line 1421. Further, the power superimposition filter 1404 is connected to the power superimposition filter 1405 and the power superimposition filter 1406 via the power line 1411. In the power superimposition filter 1404, only DC power and power having a frequency near DC can pass between the communication line 1311 and the power line 1411, and only high-frequency communication signals can pass between the communication line 1311 and the communication line 1421.

[0117] The power superimposition filter 1405 is connected to the ECU 1305 via the communication line 1312, and exchanges communication signals with or without superimposed power. The power superimposition filter 1405 is also connected to the power switch 1402 via the power line 1411 and to the transceiver 1403 via the communication line 1422. Further, the power superimposition filter 1405 is connected to the power superimposition filter 1404 and the power superimposition filter 1406 via the power line 1411. In the power superimposition filter 1405, only DC power and power having a frequency near DC can pass between the communication line 1312 and the power line 1411, and only high-frequency communication signals can pass between the communication line 1312 and the communication line 1422.

[0118] The power superimposition filter 1406 is connected to the ECU 1306 via the communication line 1313, and exchanges communication signals with or without superimposed power. The power superimposition filter 1406 is also connected to the power switch 1402 via the power line 1411 and to the transceiver 1403 via the communication line 1423. Further, the power superimposition filter 1406 is connected to the power superimposition filter 1404 and the power superimposition filter 1405 via the power line 1411. In the power superimposition filter 1406, only DC power and power having a frequency near DC can pass between the communication line 1313 and the power line 1411, and only high-frequency communication signals can pass between the communication line 1313 and the communication line 1423.

[0119] The power switch 1402 receives the power of power supply 201 supplied via the power harness 207 and the power of power supply 202 supplied via the power line 1411. Then, inside the power switch 1402, it monitors the voltage passing through the power harness 207 and the voltage passing through the power line 1411, determines which voltage to connect to the output, and switches. Thereby, the power switch 1402 supplies power to the ECU core unit 1401 via the power line 1413, to the transceiver 1403 via the power line 1412, to the sensor 231 via the power line 241, and to the actuator 232 via the power line 243, respectively.

[0120] When the power supply 201 is normal, the power switch 1402 supplies the power from the power harness 207 to the ECU core unit 1401, the transceiver 1403, the sensor 231, and the actuator 232. On the other hand, when the power supply 201 fails and the power supply 202 is normal, the power switch 1402 supplies the power transmitted through the power line 1411 to the ECU core unit 1401, the transceiver 1403, the sensor 231, and the actuator 232. Also, since the power switch 1402 can obtain the power failure information about the power supply 201, it can send the power failure information to the ECU core unit 1401 via the communication line 1424 and share the power failure information with other ECUs.

[0121] The transceiver 1403 communicates with the ECU1304 via the communication line 1311 passing through the communication line 1421 and the power superimposition filter 1404 and the communication line 1314. Also, the transceiver 1403 communicates with the ECU1305 via the communication line 1312 passing through the communication line 1422 and the power superimposition filter 1405 and the communication line 1315. Also, the transceiver 1403 communicates with the ECU1306 via the communication line 1313 passing through the communication line 1423 and the power superimposition filter 1406 and the communication line 1316. Then, the transceiver 1403 exchanges the transmission signal and the reception signal for other ECUs with the ECU core unit 1401 via the communication line 1425.

[0122] The ECU core unit 1401 controls the transceiver 1403 through the communication line 1425, and exchanges data with the ECUs 1304, 1305, and 1306 (FIG. 13) via the transceiver 1403. Further, the ECU core unit 1401 controls and exchanges data with the sensor 231 and the actuator 232, and processes the data.

[0123] As described above, according to the power supply system (power supply system 1300) according to the third embodiment, in addition to the same operational effects as those of the first embodiment, since it is a star network, the number of communication lines can be reduced as compared with the first embodiment.

[0124] <Fourth Embodiment> Next, the configuration of the power supply system according to the fourth embodiment of the present invention will be described with reference to FIG. 15.

[0125] [Configuration of Power Supply System] FIG. 15 is a system configuration diagram showing an example of power redundancy of the power supply system according to the fourth embodiment. The power supply system 1500 shown in FIG. 15 uses a ring-type network architecture similar to the power supply system 200 (FIG. 2) according to the first embodiment, reduces the power harness as compared with the first embodiment, and supplies power to the target ECU by power superposition even during normal operation of the power supply.

[0126] The power supply 201 supplies power to the ECU 1503 via the power harness 207. Further, the power supply 202 supplies power to the ECU 1504 via the power harness 211. That is, there is no power harness between the power supply 201 and the ECU 1505, and between the power supply 202 and the ECU 1506.

[0127] ECU1503 and ECU1504 can supply power to each other through power superposition via communication line 216. If power supply 201 fails, the power of power supply 202 is supplied from ECU1504 to ECU1503 via communication line 216. Conversely, when power supply 202 fails, the power of power supply 201 is supplied from ECU1503 to ECU1504 via communication line 216.

[0128] The power supply of ECU1505 is supplied through communication line 215 by power superposition via ECU1503 with the power of power supply 201. Similarly, the power supply of ECU1506 is supplied via communication line 218 by power superposition via ECU1504 with the power of power supply 202.

[0129] ECU1505 and ECU1506 can supply power to each other through power superposition via communication line 217. If power supply 201 fails, the power of power supply 202 is supplied from ECU1504 and ECU1506 to ECU1505 via communication line 217. Conversely, when power supply 202 fails, the power of power supply 201 is supplied from ECU1503 and ECU1505 to ECU1506 via communication line 217.

[0130] ECU1503 performs redundant communication with ECU1504 via communication line 216 and communication line 220, performs redundant communication with ECU1505 via communication line 215 and communication line 219, and exchanges data. Also, ECU1503 supplies power to sensor 231 via power line 241 and performs control and data exchange via communication line 242. Furthermore, ECU1503 supplies power to actuator 232 via power line 243 and performs control and data exchange via communication line 244.

[0131] ECU 1504 communicates redundantly with ECU 1503 via communication lines 216 and 220, communicates redundantly with ECU 1506 via communication lines 218 and 222, and exchanges data. Also, ECU 1504 supplies power to sensor 233 via power line 245 and performs control and data exchange via communication line 246. Further, ECU 1504 supplies power to actuator 234 via power line 247 and performs control and data exchange via communication line 248.

[0132] ECU 1505 communicates redundantly with ECU 1503 via communication lines 215 and 219, communicates redundantly with ECU 1506 via communication lines 217 and 221, and exchanges data. Also, ECU 1505 supplies power to sensor 235 via power line 249 and performs control and data exchange via communication line 250. Further, ECU 1505 supplies power to actuator 236 via power line 251 and performs control and data exchange via communication line 252.

[0133] ECU 1506 communicates redundantly with ECU 1504 via communication lines 218 and 222, communicates redundantly with ECU 1505 via communication lines 217 and 221, and exchanges data. Also, ECU 1506 supplies power to sensor 237 via power line 253 and performs control and data exchange via communication line 254. Further, ECU 1506 supplies power to actuator 238 via power line 255 and performs control and data exchange via communication line 256.

[0134] [Configuration of Electronic Control Unit] Next, the configuration of the electronic control unit (ECU) included in the power supply system 1500 will be described with reference to FIG. 16.

[0135] FIG. 16 is a block diagram showing a configuration example of the electronic control unit (ECU 1503) included in the power supply system 1500. ECU 1504 also has the same configuration as ECU 1503.

[0136] The ECU 1503 is composed of an ECU core unit 1601, a power switch 1602, a transceiver 1603, a power superimposition filter 1604, and a power superimposition filter 1605. The basic functions of each processing block are the same as those of the ECU core unit 301, the power switch 302, the transceiver 303, and the power superimposition filter 304 shown in FIG. 3.

[0137] The power superimposition filter 1604 is connected to the ECU 1504 via the communication line 216, and exchanges communication signals or communication signals with power superimposed thereon. Further, the power superimposition filter 1604 is connected to the power switch 1602 via the power line 1611 and is connected to the transceiver 1603 via the communication line 1621. Also, the power superimposition filter 1604 is connected to the power superimposition filter 1605 via the power line 1611. In the power superimposition filter 1604, only DC power and power having a frequency near DC pass between the communication line 216 and the power line 1611, and only high-frequency communication signals pass between the communication line 216 and the communication line 1621.

[0138] The power superimposition filter 1605 is connected to the ECU 1505 via the communication line 215, and exchanges communication signals or communication signals with power superimposed thereon. Further, the power superimposition filter 1605 is connected to the power switch 1602 via the power line 1611 and is connected to the transceiver 1603 via the communication line 1622. Also, the power superimposition filter 1605 is connected to the power superimposition filter 1604 via the power line 1611. In the power superimposition filter 1605, only DC power and power having a frequency near DC pass between the communication line 215 and the power line 1611, and only high-frequency communication signals pass between the communication line 215 and the communication line 1622.

[0139] The power switch 1602 receives the power of power supply 201 supplied via the power harness 207 and the power of power supply 202 supplied via the power line 1611. Inside the power switch 1602, it monitors the voltage passing through the power harness 207 and the voltage passing through the power line 1611, determines which voltage to connect to the output, and switches. Thereby, the power switch 1602 supplies power to the ECU core unit 1601 via the power line 1613, to the transceiver 1603 via the power line 1612, to the sensor 231 via the power line 241, and to the actuator 232 via the power line 243 respectively.

[0140] When power supply 201 is normal, the power switch 1602 supplies the power from the power harness 207 to the ECU core unit 1601, the transceiver 1603, the sensor 231, and the actuator 232. On the other hand, when power supply 201 fails and power supply 202 is normal, the power switch 1602 supplies the power transmitted through the power line 1611 to the ECU core unit 1601, the transceiver 1603, the sensor 231, and the actuator 232. Also, since the power switch 1602 can obtain the power failure information about power supply 201, it can send the power failure information to the ECU core unit 1601 via the communication line 1624 and share the power failure information with other ECUs.

[0141] The transceiver 1603 communicates with the ECU1504 via the communication line 216 passing through the communication line 1621 and the power superimposed filter 1604 and the communication line 220. Also, the transceiver 1603 communicates with the ECU1505 via the communication line 215 passing through the communication line 1622 and the power superimposed filter 1605 and the communication line 219. And the transceiver 1603 exchanges the transmission signal and the reception signal for other ECUs with the ECU core unit 1601 via the communication line 1625.

[0142] The ECU core unit 1601 controls the transceiver 1603 via the communication line 1625, and exchanges data with the ECU 1504, ECU 1505, and ECU 1506 (Fig. 15) via the transceiver 1603. Further, the ECU core unit 1601 controls and exchanges data with the sensor 231 and the actuator 232, and processes data.

[0143] [Configuration of Other Electronic Control Units] Next, the configuration of other electronic control units (ECUs) included in the power supply system 1500 will be described with reference to Fig. 17.

[0144] Fig. 17 is a block diagram showing a configuration example of another electronic control unit (ECU 1505) included in the power supply system 1500. The ECU 1506 also has the same configuration as the ECU 1505.

[0145] The ECU 1505 is composed of an ECU core unit 1701, a power switch 1702, a transceiver 1703, a power supply superimposed filter 1704, and a power supply superimposed filter 1705. The basic functions of each processing block are the same as those of the ECU core unit 301, the power switch 302, the transceiver 303, and the power supply superimposed filter 304 shown in Fig. 3. The wiring of the ECU 1505 is slightly different from that of the ECU 1503 by the amount that the power harness is not connected.

[0146] The power supply superimposed filter 1704 is connected to the ECU 1506 via the communication line 217, and exchanges communication signals with or without superimposed power. Further, the power supply superimposed filter 1704 is connected to the power switch 1702 via the power supply line 1711, and is connected to the transceiver 1703 via the communication line 1721. In the power supply superimposed filter 1704, only DC power and power having a frequency near DC pass between the communication line 217 and the power supply line 1711, and only high-frequency communication signals pass between the communication line 217 and the communication line 1721.

[0147] The power superimposition filter 1705 is connected to the ECU 1503 via the communication line 215, and exchanges communication signals or communication signals with superimposed power. Also, the power superimposition filter 1705 is connected to the power switch 1702 via the power line 1712 and is connected to the transceiver 1703 via the communication line 1722. In the power superimposition filter 1705, only DC power and power with a frequency near DC pass between the communication line 215 and the power line 1712, and only high-frequency communication signals pass between the communication line 215 and the communication line 1722.

[0148] The power switch 1702 receives the power of the power supply 201 supplied via the power line 1712 and the power of the power supply 202 supplied via the power line 1711. Inside the power switch 1702, the voltage passing through the power line 1712 and the voltage passing through the power line 1711 are monitored, and it is determined which voltage to connect to the output and switched. Thereby, the power switch 1702 supplies power to the ECU core unit 1701 via the power line 1714, to the transceiver 1703 via the power line 1713, to the sensor 235 via the power line 249, and to the actuator 236 via the power line 251, respectively.

[0149] When the power supply 201 is normal, the power switch 1702 supplies the power from the power line 1712 to the ECU core unit 1701, the transceiver 1703, the sensor 235, and the actuator 236. On the other hand, when the power supply 201 fails and the power supply 202 is normal, the power switch 1702 supplies the power transmitted through the power line 1711 to the ECU core unit 1701, the transceiver 1703, the sensor 235, and the actuator 236. Also, since the power switch 1702 can obtain the power failure information about the power supply 201, it can send the power failure information to the ECU core unit 1701 via the communication line 1724 and share the power failure information with other ECUs.

[0150] The transceiver 1703 communicates with the ECU 1506 via the communication line 217 through the communication line 1721 and the power supply superimposed filter 1604, and via the communication line 221. Also, the transceiver 1703 communicates with the ECU 1503 via the communication line 215 through the communication line 1722 and the power supply superimposed filter 1705, and via the communication line 219. Then, the transceiver 1703 exchanges transmission signals and reception signals for other ECUs with the ECU core unit 1701 via the communication line 1725.

[0151] The ECU core unit 1701 controls the transceiver 1703 through the communication line 1725, and exchanges data with the ECU 1503, the ECU 1504, and the ECU 1506 (FIG. 16) via the transceiver 1703. Also, the ECU core unit 1701 performs control and data exchange with the sensor 235 and the actuator 236, and processes data.

[0152] Note that the present invention can also be applied to an architecture including an integrated ECU that can receive power supply from the power supplies 201 and 202 and integrally controls a plurality of ECUs.

[0153] Furthermore, the present invention is not limited to the above-described embodiments, and of course, various other application examples and modification examples can be taken without departing from the gist of the present invention described in the claims. For example, the above-described embodiments have described the configuration in detail and specifically in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the components described. Also, a part of the configuration of one embodiment can be replaced with a component of another embodiment. Also, a component of another embodiment can be added to the configuration of one embodiment. Also, it is possible to add, replace, or delete other components for a part of the configuration of each embodiment.

[0154] Furthermore, each of the above-described configurations, functions, processing units, etc. may be realized in hardware by designing part or all of them, for example, by using an integrated circuit. As the hardware, a processor device in a broad sense such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) may be used.

[0155] Also, in the above-described embodiments, the control lines and information lines show those considered necessary for explanation, and not necessarily all the control lines and information lines are shown on the product. In reality, it may be considered that almost all components are interconnected.

Description of Reference Numerals

[0156] 200…Power supply system, 201, 202…Power supplies, 203~206…ECUs, 207, 208, 211, 212…Power harnesses, 301…ECU core unit, 302…Power switchover unit, 303…Transceiver, 304…Power superimposition filter, 401…Self-power switch, 402…Other load switch, 403…Other power switch

Claims

1. a first control circuit; a first power supply that outputs a first voltage supplied as a power supply voltage to the first control circuit; a first switch circuit connected between the first power supply and the first control circuit, for interrupting the power supply of the first voltage to the first control circuit; a second switch circuit connected to a communication line used for communication between the first power supply and a second control circuit, for interrupting the supply of the first voltage to the communication line; a second power supply that outputs a second voltage supplied as a power supply voltage to the second control circuit; a power switch circuit connected between the first control circuit and the communication line, for supplying 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; and the power supply to the second control circuit of the first voltage and the power supply to the first control circuit of the second voltage are bidirectional power transmissions using the communication line, the first switch circuit interrupts the supply of the first voltage to the first control circuit when the voltage drop of the first voltage is equal to or greater than a threshold value, the second switch circuit interrupts the supply of the first voltage to the communication line when the voltage drop of the first voltage is equal to or greater than a threshold value, the power switch circuit switches the power supply source of the power supply voltage to the first control circuit from the first power supply to the second power supply a power supply system.

2. the first switch circuit supplies the first voltage to the first control circuit when the voltage drop of the first voltage is less than a threshold value, the second switch circuit supplies the first voltage to the communication line when the voltage drop of the first voltage is less than a threshold value and the voltage drop of the second voltage is equal to or greater than a threshold value, the power switch circuit interrupts the first control circuit and the communication line The power supply system according to claim 1.

3. the first switch circuit includes a first switching element that conducts between the first power supply and the first control circuit when the voltage drop of the first voltage is less than a threshold value, and a switching element connected in series with and having a polarity opposite to that of the first switching element between the first power supply and the first control circuit; When the voltage drops of both the first voltage and the second voltage are smaller than a threshold value, the second switch circuit includes a second switching element that energizes between the first power supply and the communication line, and a switching element connected in series with the second switching element and with opposite polarity between the first power supply and the communication line. When the voltage drop of the first voltage is smaller than a threshold value, the power supply switch circuit includes a third switching element that energizes between the first control circuit and the communication line, and a switching element connected in series with the third switching element and with opposite polarity between the first control circuit and the communication line. The power supply system according to claim 1.

4. When the power supply of the first voltage to the first control circuit is cut off, the first control circuit notifies an external device that the first power supply is abnormal. The power supply system according to claim 1.

5. A first control circuit to which a first voltage is supplied as a power supply voltage from a first power supply, A first switch circuit connected to the first power supply and the first control circuit, and cutting off the power supply of the first voltage to the first control circuit, Connected to the first power supply and a communication line used for communication between a second control circuit to which a second voltage is supplied as a power supply voltage from a second power supply, and a second switch circuit that cuts off the supply of the first voltage to the communication line, A power supply switch circuit connected to the first control circuit and the communication line, and supplying 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 cut off by the first switch circuit. 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. When the voltage drop of the first voltage is equal to or greater than a threshold value, the first switch circuit cuts off the supply of the first voltage to the first control circuit. When the voltage drop of the first voltage is equal to or greater than a threshold value, the second switch circuit cuts off the supply of the first voltage to the communication line. The power supply switch circuit switches the power supply source of the power supply voltage to the first control circuit from the first power supply to the second power supply. Electronic control device.

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