Power supply system and power supply device

Abstract

To provide a power supply system and a power supply device that can appropriately stop the operation of the power supply device when a power switch is turned off.SOLUTION: The power supply system has a power supply target and a power supply device. The power supply device has a backup power supply and a power supply control circuit. When a power switch 13 is turned on, the power supply target performs an initial check and a process after starting the execution of the initial check, which is a power latch process that maintains the operating power supply even when the power switch 13 is turned off. When the power switch 13 is turned off, the power supply target generates a stop permission signal S1 to permit the power control circuit to stop operating. When the power switch 13 is turned off, the power control circuit determines whether a situation is to stop the operation of the power supply device by waiting for a reception of the stop permission signal S1, or whether to stop the power supply device without waiting for a reception of the stop permission signal S1 (step S103) depending on whether the operating power supply of the power supply target is maintained.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a power supply system and a power supply device. [Background technology]

[0002] Conventionally, there is known a power supply device that uses an auxiliary power supply to back up power supply to a power supply target when a main power supply fails. For example, the backup power supply device of Patent Document 1 is provided on a power supply line between a main power supply and an actuator driving device. When the main power supply is normal, DC power of the main power supply is supplied to the actuator driving device via the backup power supply device. When the main power supply fails, the DC power supply connected to the power supply line is switched from the main power supply to the backup power supply. The actuator driving device is applied to a steering system of a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-178481 A Summary of the Invention [Problem to be solved by the invention]

[0004] The power supply device must properly stop operation when the power switch is turned off. [Means for solving the problem]

[0005] The power supply system that can solve the above problem includes a power supply target configured to operate by consuming power from a main power supply of a vehicle, and a power supply device configured to back up power supply to the power supply target. The power supply target is configured to execute an initial check, which is an initial inspection at the time of startup, when a power switch provided in a power supply path between the main power supply and the power supply target is turned on, and a power latch process, which is a process after the start of execution of the initial check, for holding an operating power supply even when the power switch is turned off, and to generate a stop permission signal for allowing the operation of the power supply device to be stopped when the power switch is turned off. The power supply device includes an auxiliary power supply for the main power supply, and a power supply control circuit configured to control opening and closing of a charging path between the main power supply and the auxiliary power supply, and opening and closing of a discharging path between the auxiliary power supply and the power supply target. The power supply control circuit is configured to determine, depending on whether the operating power supply of the power supply target is held when the power switch is turned off, whether the situation is such that the operation of the power supply device is stopped by waiting for reception of the stop permission signal, or the situation is such that the operation of the power supply device is stopped without waiting for reception of the stop permission signal.

[0006] According to this configuration, when the operating power of the power supply target is maintained, the power supply target can operate even if the power switch is turned off. Therefore, the power supply target can generate a stop permission signal. Therefore, when the power switch is turned off and the operating power of the power supply target is maintained, the power supply control circuit can determine that it is in a state where the operation of the power supply device should be stopped by waiting for reception of the stop permission signal.

[0007] In contrast, if the operating power of the power supply target is not held, the power supply target stops operating when the power switch is turned off. Therefore, the power supply target cannot generate a stop permission signal. Therefore, when the operating power of the power supply target is not held and the power switch is turned off, the power supply control circuit can determine that the situation is such that the operation of the power supply device should be stopped without waiting for the reception of the stop permission signal.

[0008] Thus, according to the above configuration, when the power switch is turned off, the operation of the power supply device can be appropriately stopped depending on whether or not the operating power is maintained. In the above power supply system, the power supply control circuit may be configured to execute an initial check, which is an initial inspection at start-up, when the power switch is turned on, and to determine that the operation of the power supply device can be stopped when any one of a first judgment condition, a second judgment condition, and a third judgment condition is satisfied when the power switch is turned off. The first judgment condition may be that the power supply control circuit is executing the initial check, the second judgment condition may be that the operating power of the power supply target is not held, and the third judgment condition may be that the stop permission signal is received.

[0009] According to this configuration, when the power switch is turned off, if any one of the first judgment condition, the second judgment condition, and the third judgment condition is satisfied, it is judged that the operation of the power supply device can be stopped. Therefore, when the power switch is turned off, the operation of the power supply device can be appropriately stopped based on the execution state of the initial check of the power supply control circuit, the holding state of the operating power of the power supply target, and the reception state of the stop permission signal.

[0010] In the above power supply system, the power supply control circuit may be configured to determine that an abnormality has occurred in communication between the power supply control circuit and the power supply target if none of the first judgment condition, the second judgment condition, and the third judgment condition are satisfied.

[0011] When the power switch is turned off, for example, if the operating power of the power supply target is maintained through the execution of the power latch process but a stop permission signal is not received from the power supply target, there is a high probability that an abnormality has occurred in the communication between the power supply control circuit and the power supply target. According to the above configuration, it is possible to determine whether the operation of the power supply target has stopped because the operating power of the power supply target is not maintained or whether there is an abnormality in the communication.

[0012] In the above power supply system, the power supply target may be configured to set a value of a power latch flag indicating whether the operating power of the power supply target is held. In this case, the power supply control circuit may be configured to determine whether the operating power of the power supply target is held based on the value of the power latch flag.

[0013] According to this configuration, it is possible to easily determine whether the operating power of the power supply target is maintained based on the value of the power latch flag. In the above power supply system, the power supply target may include a control device of a vehicle.

[0014] The above power supply system is suitable for use in a control device for a vehicle. A power supply device that can solve the above problem includes an auxiliary power supply for a main power supply that supplies power to a power supply target, and a power supply control circuit configured to control opening and closing of a charging path between the main power supply and the auxiliary power supply, and opening and closing of a discharging path between the auxiliary power supply and the power supply target. The power supply target is configured to execute an initial check, which is an initial inspection at startup, when a power switch provided in the power supply path between the main power supply and the power supply target is turned on, and a power latch process, which is a process after the start of execution of the initial check, for holding an operating power supply even when the power switch is turned off, and to generate a stop permission signal for allowing the power supply device to stop operating when the power switch is turned off. The power supply control circuit is configured to determine whether the power supply device is in a state where it should stop operating after waiting for reception of the stop permission signal or the power supply device is in a state where it should stop operating without waiting for reception of the stop permission signal, depending on whether the operating power supply of the power supply target is held when the power switch is turned off.

[0015] According to this configuration, when the operating power of the power supply target is maintained, the power supply target can operate even if the power switch is turned off. Therefore, the power supply target can generate a stop permission signal. Therefore, when the power switch is turned off and the operating power of the power supply target is maintained, the power supply control circuit can determine that it is in a state where the operation of the power supply device should be stopped by waiting for reception of the stop permission signal.

[0016] In contrast, if the operating power of the power supply target is not held, the power supply target stops operating when the power switch is turned off. Therefore, the power supply target cannot generate a stop permission signal. Therefore, when the operating power of the power supply target is not held and the power switch is turned off, the power supply control circuit can determine that the situation is such that the operation of the power supply device should be stopped without waiting for the reception of the stop permission signal.

[0017] Thus, according to the above configuration, when the power switch is turned off, the operation of the power supply device can be appropriately stopped depending on whether or not the operating power is maintained. Effect of the Invention

[0018] According to the power supply system and power supply device of the present invention, when the power switch is turned off, the operation of the power supply device can be stopped appropriately. [Brief description of the drawings]

[0019] [Figure 1] 1 is a circuit diagram of a power supply system according to an embodiment; [Diagram 2] 5 is a flowchart showing a procedure of a stop determination process executed by a power supply control circuit according to an embodiment. [Diagram 3] 4 is a time chart showing an example of state transitions of a power supply control circuit, a first processing circuit, and a power latch flag when power is turned on according to an embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An embodiment of the power supply system will be described below. As shown in FIG. 1, the power supply system 1 has a power supply device 10 and a power supply target 12. The power supply device 10 is provided in a power supply path between a main power supply 11 and the power supply target 12. The main power supply 11 is, for example, a battery. The power supply target 12 is, for example, a vehicle control device, which operates by consuming power supplied via the power supply device 10. An example of an object controlled by the control device is, for example, a motor that is a drive source for a steering device of the vehicle. An example of the steering device is an electric power steering device or a steer-by-wire type steering device.

[0021] The power supply target 12 has a first control circuit 12A and a second control circuit 12B. The first control circuit 12A has a first processing circuit 12A1 and a first power supply relay 12A2. The first processing circuit 12A1 is, for example, a microcomputer, and has a CPU (Central Processing Unit) and a memory. The memory includes a RAM (Random-Access Memory) and a ROM (Read-Only Memory). The first processing circuit 12A1 controls the on and off of the first power supply relay 12A2.

[0022] The second control circuit 12B basically has the same configuration as the first control circuit 12A. The second control circuit 12B has a second processing circuit 12B1 and a second power supply relay 12B2. The second processing circuit 12B1 is, for example, a microcomputer, and has a CPU and a memory. The second processing circuit 12B1 controls the on and off of the second power supply relay 12B2. The first processing circuit 12A1 and the second processing circuit 12B1 exchange information with each other via a communication line (not shown).

[0023] There may be a master-slave relationship between the first control circuit 12A and the second control circuit 12B. In this case, for example, the first control circuit 12A functions as a master and the second control circuit 12B functions as a slave. However, depending on the product specifications, the first control circuit 12A and the second control circuit 12B may have an equal relationship.

[0024] The power supply path has a first power line L1 and a second power line L2. The first power line L1 and the second power line L2 connect the main power supply 11 and the power supply target 12 via the power supply device 10. The second power line L2 connects a first connection point P1 set on the first power line L1 and the first processing circuit 12A1. The first connection point P1 is set between the main power supply 11 and the power supply device 10 on the first power line L1. The power of the main power supply 11 can be supplied to the first processing circuit 12A1 via the first power line L1 and the second power line L2. The first power relay 12A2 is provided on the second power line L2. The first power relay 12A2 opens and closes the second power line L2.

[0025] The power supply path has a third power line L3 and a fourth power line L4. The third power line L3 connects a second connection point P2 set on the first power line L1 to the second processing circuit 12B1. The second connection point P2 is set between the first connection point P1 on the first power line L1 and the power supply device 10. The fourth power line L4 connects a third connection point P3 set on the second power line L2 to the second processing circuit 12B1. The third connection point P3 is set between the first connection point P1 on the second power line L2 and the power supply device 10. The power of the main power supply 11 can be supplied to the second processing circuit 12B1 via the third power line L3 and the fourth power line L4. The second power relay 12B2 is provided on the fourth power line L4. The second power relay 12B2 opens and closes the fourth power line L4.

[0026] A power switch 13 is provided in the first power line L1 between the first connection point P1 and the second connection point P2. The power switch 13 includes, for example, an ignition switch, and is operated when starting to run the vehicle. Through the operation of the power switch 13, the conduction of the first power line L1 is switched between on and off. Turning on the power switch 13 is equivalent to turning on the power of the power supply target 12. Turning off the power switch 13 is equivalent to opening the power supply of the power supply target 12.

[0027] <Configuration of power supply device 10> Next, the configuration of the power supply device 10 will be described. The power supply device 10 has a charging circuit 21, an auxiliary power supply 22, a boost circuit 23, and a power supply control circuit 24. The power supply device 10 also has first to third switches 31 to 33, and a voltage sensor 41.

[0028] The charging circuit 21 is a circuit for charging the auxiliary power supply 22 using power from the main power supply 11. An input terminal of the charging circuit 21 is connected to a fourth connection point P4 set on the second power supply line L2 via a fifth power supply line L5. An output terminal of the charging circuit 21 is connected to the auxiliary power supply 22 via a sixth power supply line L6.

[0029] Auxiliary power supply 22 is a power storage device capable of charging and discharging electric charge, and may be, for example, a lithium ion capacitor or a lithium ion battery. The voltage of auxiliary power supply 22 is set lower than the voltage of main power supply 11. The voltage of auxiliary power supply 22 and the voltage of main power supply 11 are each a terminal voltage, and are actual output voltages.

[0030] The boost circuit 23 is a circuit for boosting the output voltage of the auxiliary power supply 22. The boost circuit 23 boosts the output voltage of the auxiliary power supply 22 to a voltage higher than the terminal voltage of the auxiliary power supply 22 and lower than the terminal voltage of the main power supply 11, for example.

[0031] An input terminal of the boost circuit 23 is connected to the auxiliary power supply 22 via a seventh power line L7. The boost circuit 23 has two output terminals. A first output terminal of the boost circuit 23 is connected to a fifth connection point P5 set on the first power line L1 via an eighth power line L8. The fifth connection point P5 is set between the second connection point P2 on the first power line L1 and the power supply target 12. A second output terminal of the boost circuit 23 is connected to a sixth connection point P6 set on the second power line L2 via a ninth power line L9. The sixth connection point P6 is set between the fourth connection point P4 on the second power line L2 and the power supply target 12.

[0032] The first switch 31 is provided in the fifth power line L5. The first switch 31 opens and closes the fifth power line L5. The second switch 32 is provided in the eighth power line L8. The second switch 32 opens and closes the eighth power line L8. The third switch 33 is provided in the ninth power line L9. The third switch 33 opens and closes the ninth power line L9.

[0033] The voltage sensor 41 is provided between the second connection point P2 and the fifth connection point P5 in the first power supply line L1. The voltage sensor 41 detects a voltage V1 generated in the first power supply line L1.

[0034] The power supply control circuit 24 is connected to a seventh connection point P7 set on the fifth power supply line L5 via a tenth power supply line L10. The seventh connection point P7 is set between the first switch 31 and the charging circuit 21 on the fifth power supply line L5. The power supply control circuit 24 is also connected to an eighth connection point P8 set on the first power supply line L1 via an eleventh power supply line L11. The eighth connection point P8 is set between the fifth connection point P5 on the first power supply line L1 and the power supply target 12.

[0035] The power supply control circuit 24 controls the on and off of the first to third switches 31 to 33. The power supply control circuit 24 detects the on and off of the power switch 13 based on the voltage V1 detected via the voltage sensor 41. The power supply control circuit 24 monitors the voltage of the main power supply 11. When the value of the voltage VB of the main power supply 11 is smaller than a defined voltage threshold, the power supply control circuit 24 determines that the voltage VB of the main power supply 11 has dropped. The voltage threshold is a criterion for determining a voltage drop of the main power supply 11.

[0036] The fifth power line L5 and the sixth power line L6 form a charging path between the main power supply 11 and the auxiliary power supply 22. The seventh power line L7, the eighth power line L8, and the ninth power line L9 form a discharging path between the auxiliary power supply 22 and the power supply target 12. The power supply control circuit 24 controls the opening and closing of the charging path and the discharging path by controlling the on and off of the first to third switches 31 to 33.

[0037] <Operation of power supply target 12 when power is turned on> Next, a description will be given of the operation of the power supply target 12 when the power is turned on, that is, when the power switch 13 is turned on. In the initial state, the first power relay 12A2 and the second power relay 12B2 are turned off.

[0038] When the power switch 13 is turned on, power from the main power supply 11 is supplied to the first processing circuit 12A1 via the first power line L1. The first processing circuit 12A1 is started when the power is turned on, and performs an initial check. The initial check is an initial inspection before starting to execute control of the controlled object, and includes, for example, a check of the hardware, initialization of the CPU, and initialization of variables or flags.

[0039] When the first processing circuit 12A1 normally completes the inspection of a specific inspection item among a plurality of inspection items to be inspected by the initial check, the first processing circuit 12A1 executes a power latch process. The power latch process is a process for maintaining the operating power of the first processing circuit 12A1 even if the power switch 13 is turned off. Specifically, the first processing circuit 12A1 turns on the first power relay 12A2. Therefore, the power from the main power supply 11 is supplied to the first processing circuit 12A1 not only through the first power supply line L1 but also through the second power supply line L2. Even if the power supply from the main power supply 11 to the first processing circuit 12A1 through the first power supply line L1 is interrupted, the power supply from the main power supply 11 to the first processing circuit 12A1 through the second power supply line L2 is maintained.

[0040] When the initial check is normally completed, the first processing circuit 12A1 starts executing normal control. The normal control is to control the controlled object in a normal state where there is no abnormality in the first control circuit 12A including the first processing circuit 12A1 and the controlled object of the first control circuit 12A.

[0041] When the power switch 13 is turned on, the power from the main power supply 11 is supplied to the second processing circuit 12B1 via the third power line L3. The second processing circuit 12B1 is started when the power is turned on and performs an initial check. When a specific inspection item among a plurality of inspection items to be inspected by the initial check is normally completed, the second processing circuit 12B1 performs a power latch process. The power latch process is a process for holding the operating power of the second processing circuit 12B1 even when the power switch 13 is turned off. Specifically, the second processing circuit 12B1 turns on the second power relay 12B2. Therefore, the power from the main power supply 11 is supplied to the first processing circuit 12A1 not only via the third power line L3 but also via the fourth power line L4. Even if the power supply from the main power supply 11 to the second processing circuit 12B1 via the third power supply line L3 is interrupted, the power supply from the main power supply 11 to the second processing circuit 12B1 via the fourth power supply line L4 is maintained.

[0042] <Operation of power supply target 12 when power is released> Next, a description will be given of the operation of the power supply target 12 when the power supply is opened, that is, when the power switch 13 is turned off. In the initial state, the first power supply relay 12A2 and the second power supply relay 12B2 are turned on.

[0043] When the power switch 13 is turned off, the first processing circuit 12A1 keeps the first power relay 12A2 in the on state. Therefore, even if the power supply from the main power source 11 to the first processing circuit 12A1 via the first power line L1 is interrupted, the power supply from the main power source 11 to the first processing circuit 12A1 via the second power line L2 is maintained. Therefore, even after the power switch 13 is turned off, the first processing circuit 12A1 can operate.

[0044] When the power switch 13 is turned off, the second processing circuit 12B1 keeps the second power relay 12B2 in the on state. Therefore, even if the power supply from the main power supply 11 to the second processing circuit 12B1 via the third power supply line L3 is cut off, the power supply from the main power supply 11 to the second processing circuit 12B1 via the fourth power supply line L4 is maintained. Therefore, even after the power switch 13 is turned off, the second processing circuit 12B1 can operate.

[0045] When the power switch 13 is turned off, the first processing circuit 12A1 and the second processing circuit 12B1 execute a stop determination process. The stop determination process is a process for determining whether the first processing circuit 12A1 and the second processing circuit 12B1 may stop their respective operations. The stop determination process includes a process for the first processing circuit 12A1 and the second processing circuit 12B1 to confirm with each other whether they recognize that the power switch 13 is turned off.

[0046] When it is determined that the power switch 13 is turned off, the first processing circuit 12A1 generates a first electrical signal indicating that the power switch 13 is turned off and transmits the generated first electrical signal to the second processing circuit 12B1. When it is determined that the power switch 13 is turned off, the second processing circuit 12B1 generates a second electrical signal indicating that the power switch 13 is turned off and transmits the generated second electrical signal to the first processing circuit 12A1.

[0047] When the first processing circuit 12A1 determines based on the second electrical signal that the second processing circuit 12B1 recognizes that the power switch 13 is off, it generates a stop permission signal S1 for the power supply device 10 and transmits the generated stop permission signal S1 to the power supply device 10. The stop permission signal S1 is an electrical signal for permitting the power supply device 10 to stop operating.

[0048] After transmitting the stop permission signal S1, the first processing circuit 12A1 executes a determined end sequence. The end sequence is a series of processes executed to normally end the function of the controlled object. The processes include, for example, a process of stopping the process being executed by the first processing circuit 12A1, and a process of waiting until the process being executed by the first processing circuit 12A1 is completed and storing data temporarily stored in the working area of ​​the memory in the non-volatile storage area of ​​the memory. After completing the execution of the end sequence, the first processing circuit 12A1 turns off the first power relay 12A2. Since the power supply to the first processing circuit 12A1 is cut off, the first processing circuit 12A1 stops operating.

[0049] When it is determined based on the first electrical signal that the first processing circuit 12A1 recognizes that the power switch 13 is off, the second processing circuit 12B1 executes a determined termination sequence. After completing the execution of the termination sequence, the second processing circuit 12B1 turns off the second power relay 12B2. Since the power supply to the second processing circuit 12B1 is cut off, the second processing circuit 12B1 stops operating.

[0050] <Operation of power supply device 10 when power is turned on> Next, a description will be given of the operation of the power supply device 10 when the power is turned on, that is, when the power switch 13 is turned on. In the initial state, the power switch 13 and the first to third switches 31 to 33 are turned off.

[0051] When the power switch 13 is turned on, power from the main power supply 11 is supplied to the power supply control circuit 24 via the eleventh power line L11. The power supply control circuit 24 starts up when the power is turned on and executes an initial check. The initial check is an initial inspection before the power supply device 10 is operated, and includes, for example, a hardware check, initialization of the CPU, and initialization of variables or flags, etc.

[0052] When the initial check is normally completed, the power supply control circuit 24 performs processing for transitioning the state of the power supply device 10 to a backup standby state for the first processing circuit 12A1. That is, the power supply control circuit 24 turns on the first switch 31 and the second switch 32, while maintaining the third switch 33 in an off state. With the first switch 31 being turned on, power from the main power supply 11 is charged into the auxiliary power supply 22 via the charging circuit 21. The charging circuit 21 controls charging while, for example, monitoring the charging current and charging voltage.

[0053] The backup standby state is a state in which the power supply device 10 is capable of backing up the power supply to the first control circuit 12A, that is, a state in which the power supply device 10 is on standby to back up the power supply to the first control circuit 12A. When the power supply device 10 is maintained in the backup standby state, the voltage VB of the main power supply 11 does not drop, and power is supplied from the main power supply 11 to the power supply target 12 via the first power supply line L1 and the second power supply line L2.

[0054] The output voltage of the auxiliary power supply 22 is boosted by the boost circuit 23. When the voltage VB of the main power supply 11 has not dropped, the voltage V2 boosted by the boost circuit 23 is lower than the voltage VB of the main power supply 11. For this reason, the voltage V2 boosted by the boost circuit 23 is not supplied to the first processing circuit 12A1 via the eighth power supply line L8 and the first power supply line L1.

[0055] A first diode (not shown) for preventing reverse current is provided between the fifth connection point P5 in the eighth power line L8 and the second switch 32. The first diode prevents power from flowing from the main power supply 11 to the boost circuit 23 via the first power line L1 and the eighth power line L8.

[0056] When the voltage VB of the main power supply 11 drops, power from the boost circuit 23 is instantly supplied to the first processing circuit 12A1 via the eighth power supply line L8 and the first power supply line L1. This is because, as the voltage VB of the main power supply 11 drops, the voltage V2 boosted by the boost circuit 23 becomes higher than the voltage VB of the main power supply 11 and, by extension, the voltage generated on the first power supply line L1. Therefore, even if the power supply from the main power supply 11 to the power supply target 12 is interrupted, the power supply to the first processing circuit 12A1 via the first power supply line L1 is backed up by the auxiliary power supply 22.

[0057] A second diode (not shown) for preventing reverse current is provided between the voltage sensor 41 and the fifth connection point P5 in the first power line L1. The second diode prevents power from flowing from the boost circuit 23 to the main power supply 11 via the eighth power line L8 and the first power line L1.

[0058] When the voltage VB of the main power supply 11 drops, the power supply control circuit 24 turns on the third switch 33. As a result, power from the boost circuit 23 is supplied to the first processing circuit 12A1 via the ninth power supply line L9 and the second power supply line L2. This is because, as the voltage VB of the main power supply 11 drops, the voltage V2 boosted by the boost circuit 23 becomes higher than the voltage VB of the main power supply 11 and thus the voltage generated on the second power supply line L2. Therefore, even if the power supply from the main power supply 11 to the power supply target 12 is interrupted, the power supply to the first processing circuit 12A1 via the second power supply line L2 is backed up by the auxiliary power supply 22.

[0059] A third diode (not shown) for preventing reverse current is provided between the fourth connection point P4 and the sixth connection point P6 in the second power line L2. The third diode prevents power from flowing from the boost circuit 23 to the main power supply 11 via the ninth power line L9 and the second power line L2.

[0060] <Operation of power supply device 10 when power is disconnected> Next, the operation of the power supply device 10 when the power supply is opened, i.e., when the power switch 13 is turned off, will be described. In the initial state, the power switch 13, the first switch 31, and the second switch 32 are on, and the third switch 33 is off. The voltage VB of the main power supply 11 has not decreased.

[0061] When the power switch 13 is turned off, the supply of power from the main power supply 11 to the power supply control circuit 24 via the eleventh power supply line L11 is stopped. However, when the power switch 13 is turned off, the power supply control circuit 24 waits until it receives a stop permission signal S1 from the first processing circuit 12A1. That is, the first switch 31 and the second switch 32 are maintained in the on state. Therefore, the supply of power from the main power supply 11 to the power supply control circuit 24 via the tenth power supply line L10 is continued. Therefore, even after the power switch 13 is turned off, the power supply control circuit 24 can continue to operate.

[0062] When the power supply control circuit 24 receives the stop permission signal S1 from the first processing circuit 12A1, it executes a determined termination sequence. The termination sequence is a series of processes executed to normally terminate the function of the power supply device 10. After the termination sequence is normally completed, the power supply control circuit 24 turns off the first switch 31 and the second switch 32. By turning off the first switch 31, the supply of power from the main power supply 11 to the power supply control circuit 24 via the tenth power line L10 is cut off. This causes the operation of the power supply control circuit 24, and therefore the operation of the power supply device 10, to stop.

[0063] The power supply device 10 configured in this manner has the following concerns. That is, the first power relay 12A2 is maintained in an OFF state during the period from when the first processing circuit 12A1 starts executing the initial check until the inspection of a specific inspection item among the multiple inspection items to be inspected by the initial check is normally completed. Therefore, if the power switch 13 is turned off at the timing when the first power relay 12A2 is maintained in an OFF state during the execution of the initial check, the first processing circuit 12A1 stops operating. Therefore, the first processing circuit 12A1 cannot generate a stop permission signal S1 for the power supply device 10. Therefore, even if the power switch 13 is turned off, the power supply device 10 cannot stop operating. That is, the power supply device 10 is maintained in a state of waiting for reception of the stop permission signal S1. Since the power supply control circuit 24 does not receive the stop permission signal S1 even though the power switch 13 is turned off, there is a risk that the power supply control circuit 24 may erroneously determine that an abnormality has occurred in the communication between the power supply device 10 and the first control circuit 12A, for example.

[0064] Therefore, in this embodiment, the power supply device 10 has the following configuration. <Power supply shutdown determination process> The first processing circuit 12A1 sets the value of the power latch flag F1 according to the state of the first power relay 12A2. The power latch flag F1 is information indicating whether the first power relay 12A2 is on or off. When the first power relay 12A2 is off, the first processing circuit 12A1 sets the value of the power latch flag F1 to "off (OFF)". When the first power relay 12A2 is on, the first processing circuit 12A1 sets the value of the power latch flag F1 to "on (ON)". The power supply control circuit 24 is capable of taking in the value of the power latch flag F1.

[0065] When the power switch 13 is turned off, the power supply control circuit 24 performs a stop determination process. The stop determination process is a process for determining whether or not it is acceptable to stop the operation of the power supply device 10. When a set stop determination condition is met, the power supply control circuit 24 determines that it is acceptable to stop the operation of the power supply device 10, and starts executing a termination sequence. The stop determination conditions include first to third determination conditions A1 to A3.

[0066] A1. The initial check of the power supply 10 is being performed. A2. The value of power latch flag F1 is “off”. A3. The power supply control circuit 24 receives the stop permission signal S1.

[0067] When the power switch 13 is turned off and any one of the first to third judgment conditions A1 to A3 is satisfied, the power supply control circuit 24 determines that it is acceptable to stop the operation of the power supply device 10, and starts executing the shutdown sequence.

[0068] The first judgment condition A1 is set based on the following viewpoint: That is, the master-slave relationship between the first processing circuit 12A1 and the power supply control circuit 24 is dissolved during the execution of the initial check of the power supply device 10. When the power switch 13 is turned off during the period during which the master-slave relationship between the first processing circuit 12A1 and the power supply control circuit 24 is dissolved, the power supply control circuit 24 judges that the operation of the power supply device 10 may be stopped without waiting for the reception of the stop permission signal S1.

[0069] The second judgment condition A2 is set based on the following viewpoint. That is, when the power switch 13 is turned off while the value of the power latch flag F1 is "off", the power required for the operation of the first processing circuit 12A1 cannot be secured, and the operation of the first processing circuit 12A1 stops. Therefore, the first processing circuit 12A1 cannot generate the stop permission signal S1. When the first processing circuit 12A1 stops its operation, the communication between the first processing circuit 12A1 and the power control circuit 24 is also cut off. When the power supply target 12 is performing an initial check, the value of the power latch flag F1 is set to "off". When the power switch 13 is turned off in such a case, the power control circuit 24 judges that the operation of the power supply device 10 may be stopped without waiting for the reception of the stop permission signal S1.

[0070] The third judgment condition A3 is a basic condition for stopping the operation of the power supply device 10. When the stop permission signal S1 is received, the power supply control circuit 24 judges that the operation of the power supply device 10 may be stopped.

[0071] The first judgment condition A1 and the second judgment condition A2 are conditions for judging whether the situation is such that the operation of the power supply device 10 is stopped by waiting for reception of the stop permission signal S1 when the power switch 13 is turned off, or the situation is such that the operation of the power supply device 10 is stopped without waiting for reception of the stop permission signal S1. When the power switch 13 is turned off and neither the first judgment condition A1 nor the second judgment condition A2 is satisfied, the power supply control circuit 24 judges that the situation is such that the operation of the power supply device 10 is stopped by waiting for reception of the stop permission signal S1. When the power switch 13 is turned off and either the first judgment condition A1 or the second judgment condition A2 is satisfied, the power supply control circuit 24 judges that the situation is such that the operation of the power supply device 10 is stopped without waiting for reception of the stop permission signal S1.

[0072] When the power switch 13 is turned off and none of the first to third judgment conditions A1 to A3 are satisfied, the power supply control circuit 24 judges that an abnormality has occurred in the communication between the power supply device 10 and the first control circuit 12A.

[0073] This is based on the following viewpoint. That is, when the stop permission signal S1 cannot be received while the value of the power latch flag F1 is "on", it is considered that the communication between the first processing circuit 12A1 and the power supply control circuit 24 has been interrupted even though the power required for the operation of the first processing circuit 12A1 is being supplied. Therefore, it is considered highly likely that an abnormality has occurred in the communication between the first processing circuit 12A1 and the power supply control circuit 24.

[0074] The power supply control circuit 24 may execute a prescribed notification process when it is determined that an abnormality has occurred in the communication between the power supply device 10 and the first control circuit 12A. The notification process is a process for notifying that an abnormality has occurred in the communication. When the power supply target 12 is a control device of a vehicle, the power supply control circuit 24 may, for example, appeal to the visual or auditory sense of the user of the vehicle and leave the occurrence of an abnormality in the communication between the power supply device 10 and the first control circuit 12A unattended.

[0075] <Procedure for determining whether the power supply is stopped> The power supply control circuit 24 may determine whether the first to third determination conditions A1 to A3 are satisfied in a predetermined order. An example of the procedure of the stop determination process executed by the power supply control circuit 24 is as follows.

[0076] 2, when the power switch 13 is turned off, the power supply control circuit 24 determines whether an initial check of the power supply device 10 is being executed (step S101). When it is determined that an initial check is being executed (YES in step S101), the power supply control circuit 24 determines that the operation of the power supply device 10 may be stopped (step S102), and starts executing a termination sequence.

[0077] When it is determined that the initial check is not being performed (NO in step S101), the power supply control circuit 24 determines whether the value of the power latch flag F1 is "off" (step S103). When the value of the power latch flag F1 is "off" (YES in step S103), the power supply control circuit 24 determines that the operation of the power supply device 10 may be stopped (step S102), and starts the execution of the termination sequence.

[0078] When the value of the power latch flag F1 is not "off" (NO in step S103), the power supply control circuit 24 determines whether or not a stop permission signal S1 has been received (step S104). When it is determined that the stop permission signal S1 has been received (YES in step S104), the power supply control circuit 24 determines that the operation of the power supply device 10 may be stopped (step S102), and starts executing the termination sequence.

[0079] When it is determined that the stop permission signal S1 has not been received (NO in step S104), the power supply control circuit 24 determines that an abnormality has occurred in the communication between the power supply device 10 and the first control circuit 12A (step S105), and ends the process.

[0080] <Operation of this embodiment> Next, the operation of this embodiment will be described. 3, the first processing circuit 12A1 starts executing an initial check when the power is turned on (time T1). When a specific test item among a plurality of test items to be tested by the initial check is normally completed, the first processing circuit 12A1 turns on the first power relay 12A2 and sets the value of the power latch flag F1 to "on" (time T2). The value of the power latch flag F1 is maintained at "off" from the start of the execution of the initial check until the test of the specific test item is normally completed.

[0081] When the power supply is turned on, the power supply control circuit 24 starts executing an initial check of the power supply device 10 (time T1). When the initial check is completed normally (time T3), the power supply control circuit 24 transitions the state of the power supply device 10 to a backup standby state. In the example of FIG. 3, the timing at which the power supply control circuit 24 completes the initial check is earlier than the timing at which the initial check of the first processing circuit 12A1 is completed. Also, the timing at which the power supply control circuit 24 completes the initial check is earlier than the timing at which the value of the power latch flag F1 is set to "ON".

[0082] If the power switch 13 is turned off within the period ΔT1 from the start to the completion of the initial check of the power supply device 10, the power supply control circuit 24 starts the execution of the termination sequence even if it has not received the stop permission signal S1 from the first processing circuit 12A1. This is due to the positive determination in step S101 in FIG. 2.

[0083] When the power switch 13 is turned off after the state of the power supply device 10 has transitioned to the backup standby state, the power supply control circuit 24 cannot start execution of the termination sequence unless it receives a stop permission signal S1 from the first processing circuit 12A1. This is based on the viewpoint that the first processing circuit 12A1 is positioned higher than the power supply control circuit 24 after the state of the power supply device 10 has transitioned to the backup standby state.

[0084] When the power switch 13 is turned off after the value of the power latch flag F1 is set to "on", power from the main power supply 11 is supplied to the first processing circuit 12A1 via the second power line L2. Therefore, the first processing circuit 12A1 generates a stop permission signal S1 when the power switch 13 is turned off, and transmits the generated stop permission signal S1 to the power supply control circuit 24. Therefore, the power supply control circuit 24 starts executing the termination sequence by receiving the stop permission signal S1 from the first processing circuit 12A1. This is due to the positive determination at step S104 in FIG. 2.

[0085] If the power switch 13 is turned off within a period ΔT2 from the completion of the initial check of the power supply device 10 to the setting of the value of the power latch flag F1 to "on", the power supply from the main power supply 11 to the first processing circuit 12A1 via the first power line L1 is cut off. In addition, since the first power relay 12A2 is maintained in the off state, the power supply from the main power supply 11 to the first processing circuit 12A1 via the second power line L2 is also cut off. Therefore, the first processing circuit 12A1 cannot generate the stop permission signal S1. Therefore, the power supply control circuit 24 cannot receive the stop permission signal S1 from the first processing circuit 12A1. However, in this case, the power supply control circuit 24 starts the execution of the termination sequence even if it does not receive the stop permission signal S1 from the first processing circuit 12A1. This is due to the positive determination at step S103 in FIG. 2.

[0086] <Effects of the embodiment> This embodiment provides the following advantages. (1) When the power switch 13 is turned off, the power supply control circuit 24 determines whether the operation of the power supply device 10 is to be stopped upon receipt of the stop permission signal S1 or whether the operation of the power supply device 10 is to be stopped without waiting for receipt of the stop permission signal S1, depending on whether the operating power of the power supply target 12 is maintained. Determining whether the operating power of the power supply target 12 is maintained means determining whether the value of the power latch flag F1 is "ON".

[0087] According to this configuration, when the operating power of the power supply target 12 is maintained, the power supply target 12 can operate even if the power switch 13 is turned off. Therefore, the power supply target 12 can generate the stop permission signal S1. Therefore, when the power supply switch 13 is turned off and the operating power of the power supply target 12 is maintained, the power supply control circuit 24 can determine that it is a situation in which the operation of the power supply device 10 should be stopped by waiting for reception of the stop permission signal S1.

[0088] In contrast, if the operating power of the power supply target 12 is not maintained, the power supply target 12 stops operating when the power switch 13 is turned off. Therefore, the power supply target 12 cannot generate the stop permission signal S1. Therefore, when the power supply switch 13 is turned off in a case where the operating power of the power supply target 12 is not maintained, the power supply control circuit 24 can determine that the situation is such that the operation of the power supply device 10 should be stopped without waiting for the reception of the stop permission signal S1.

[0089] Thus, according to this embodiment, when the power switch 13 is turned off, the operation of the power supply device 10 can be appropriately stopped depending on whether the operating power is maintained.

[0090] (2) When the power switch 13 is turned on, the power supply control circuit 24 executes an initial check, which is an initial inspection at the time of start-up. When the power switch 13 is turned off, the power supply control circuit 24 determines that it is possible to stop the operation of the power supply device 10 if any one of the first judgment condition, the second judgment condition, and the third judgment condition is satisfied.

[0091] The first condition is that the power supply control circuit 24 is performing an initial check. The second condition is that the operating power supply of the power supply target 12 is not held, that is, the value of the power latch flag F1 is set to "off." The third condition is that the power supply control circuit 24 receives the stop permission signal S1.

[0092] According to this configuration, when the power switch 13 is turned off, if any one of the first judgment condition, the second judgment condition, and the third judgment condition is satisfied, it is judged that it is possible to stop the operation of the power supply device 10. Therefore, when the power switch 13 is turned off, the operation of the power supply device 10 can be appropriately stopped based on the execution state of the initial check of the power supply control circuit 24, the holding state of the operating power of the power supply target 12, and the reception state of the stop permission signal S1.

[0093] (3) If none of the first judgment condition, the second judgment condition, and the third judgment condition is satisfied, the power supply control circuit 24 judges that an abnormality has occurred in communication between the power supply control circuit 24 and the power supply target 12.

[0094] When the power switch 13 is turned off, for example, if the operating power of the power supply target 12 is maintained through execution of the power latch process but the stop permission signal S1 is not received from the power supply target 12, there is a high probability that an abnormality has occurred in the communication between the power supply control circuit 24 and the power supply target 12. According to the above configuration, it is possible to determine whether the operation of the power supply target 12 has stopped because the operating power of the power supply target 12 is not maintained, or whether there is an abnormality in the communication.

[0095] (4) The power supply target 12 sets the value of the power latch flag F1 indicating whether or not the operating power of the power supply target 12 is being held. The power supply control circuit 24 determines whether or not the operating power of the power supply target 12 is being held based on the value of the power latch flag F1. With this configuration, the power supply control circuit 24 can easily determine whether or not the operating power of the power supply target 12 is being held based on the value of the power latch flag F1.

[0096] (5) When the power switch 13 is turned off, the power supply control circuit 24 determines whether or not it is acceptable to stop the operation of the power supply device 10 based on the value of the power latch flag F1, i.e., based on whether or not the operating power of the power supply target 12 is maintained. This makes it possible to simplify the process for determining whether or not it is acceptable to stop the operation of the power supply device 10.

[0097] Incidentally, the power supply control circuit 24 may have the following configuration. For example, when the power supply switch 13 is turned off, if the power supply control circuit 24 does not receive the stop permission signal S1 within a predetermined waiting time after the power supply switch 13 is turned off, the power supply control circuit 24 stops the operation of the power supply device 10 without waiting for the stop permission signal S1 to be received. However, in this case, it is necessary to take into consideration, for example, a situation in which the power supply switch 13 is turned on again while waiting for the stop permission signal S1 to be received. There are a huge number of situations to consider other than the power supply switch 13 being turned on again.

[0098] (6) Power supply target 12 includes a vehicle control device. Power supply system 1 according to the present embodiment is suitable for a vehicle control device. <Other embodiments> This embodiment may be modified as follows.

[0099] Depending on the product specifications, the first judgment condition among the first to third judgment conditions A1 to A3 for judging whether or not the operation of the power supply device 10 may be stopped may be omitted. In this case, the process of step S101 in Fig. 2 may be omitted. That is, when the power switch 13 is turned off, the power supply control circuit 24 shifts the process to step S103.

[0100] The power supply target 12 may be a control device having only the first control circuit 12A. In this case, the third power line L3 and the fourth power line L4 can be omitted. [Explanation of symbols]

[0101] 1. Power supply system 10…Power supply device 11…Main power supply 12…Power supply target 13...Power switch 22…Auxiliary power supply 24...Power supply control circuit F1…Power latch flag L5: The fifth power line that constitutes the charging path L6: The sixth power line that constitutes the charging path L7: The seventh power line that constitutes the discharge path L8: The eighth power line that constitutes the discharge path L9: The ninth power line that constitutes the discharge path S1…Stop permission signal

Claims

1. A power supply target configured to operate by consuming power from a main power supply of a vehicle; A power supply device configured to back up power supply to the power supply target, the power supply target is configured to execute, when a power switch provided in a power supply path between the main power source and the power supply target is turned on, an initial check which is an initial inspection at the time of startup, and a power latch process which is a process after the start of execution of the initial check and which holds an operating power source even when the power switch is turned off, and to generate a stop permission signal for permitting the operation of the power supply device to be stopped when the power switch is turned off, The power supply device includes: an auxiliary power supply for the main power supply; a power supply control circuit configured to control opening and closing of a charging path between the main power supply and the auxiliary power supply, and opening and closing of a discharging path between the auxiliary power supply and the power supply target, The power supply system is configured so that, when the power switch is turned off, the power supply control circuit determines, depending on whether the operating power source of the power supply target is maintained, whether the operation of the power supply device is to be stopped after waiting for receipt of the stop permission signal, or whether the operation of the power supply device is to be stopped without waiting for receipt of the stop permission signal.

2. the power supply control circuit is configured to, when the power switch is turned on, execute an initial check which is an initial inspection at the time of start-up, and, when the power switch is turned off, determine that it is possible to stop the operation of the power supply device when any one of a first judgment condition, a second judgment condition, and a third judgment condition is satisfied; the first determination condition being that the power supply control circuit is executing the initial check; the second determination condition being that the operating power supply of the power supply target is not held; 2. The power supply system according to claim 1, wherein the third determination condition is that the stop permission signal has been received.

3. 3. The power supply system according to claim 2, wherein the power supply control circuit is configured to determine that an abnormality has occurred in communication between the power supply control circuit and the power supply target if none of the first judgment condition, the second judgment condition, and the third judgment condition are satisfied.

4. The power supply target is configured to set a value of a power latch flag indicating whether an operating power supply of the power supply target is maintained; The power supply system according to any one of claims 1 to 3, wherein the power supply control circuit is configured to determine whether the operating power supply of the power supply target is maintained based on the value of the power latch flag.

5. 4. The power supply system according to claim 1, wherein the power supply target includes a control device of a vehicle.

6. An auxiliary power source for a main power source that supplies power to a power supply target; A power supply control circuit configured to control opening and closing of a charging path between the main power supply and the auxiliary power supply, and opening and closing of a discharging path between the auxiliary power supply and the power supply target, the power supply target is configured to execute, when a power switch provided in a power supply path between the main power source and the power supply target is turned on, an initial check which is an initial inspection at the time of startup, and a power latch process which is a process after the start of execution of the initial check and which holds an operating power source even when the power switch is turned off, and to generate a stop permission signal for permitting the operation of the power supply device to be stopped when the power switch is turned off, The power supply device is configured so that, when the power switch is turned off, the power supply control circuit determines, depending on whether the operating power source of the power supply target is maintained, whether the operation of the power supply device is to be stopped after waiting for receipt of the stop permission signal, or whether the operation of the power supply device is to be stopped without waiting for receipt of the stop permission signal.

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