In-vehicle control device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-08-13
Smart Images
Figure JP2026003701_13082026_PF_FP_ABST
Abstract
Description
In-vehicle control device
[0001] The present disclosure relates to an in-vehicle control device.
[0002] Patent Document 1 discloses an electric vehicle. This electric vehicle includes a high-voltage battery, a high-voltage wiring to which the voltage of the high-voltage battery is applied, a low-voltage battery, a low-voltage wiring to which the voltage of the low-voltage battery is applied, and a first voltage converter and a second voltage converter connected in parallel between the high-voltage wiring and the low-voltage wiring. The motor, which is a high-voltage load, is driven by the power of the high-voltage battery. The shift-by-wire device and the system controller, which are low-voltage loads, are driven by the power stepped down by the first voltage converter or the second voltage converter.
[0003] Japanese Patent Application Laid-Open No. 2018-121397
[0004] In the configuration disclosed in Patent Document 1, when the high-voltage battery fails, the driving of the high-voltage load and the driving of the low-voltage load by the power obtained by stepping down the output voltage of the high-voltage battery become impossible.
[0005] An object of the present disclosure is to provide a technique that makes it easy to continue driving a high-voltage load and driving a low-voltage load by power obtained by stepping down the output voltage of a high-voltage power source even when the high-voltage power source fails.
[0006] The in-vehicle control device of the present disclosure is an in-vehicle control device included in an in-vehicle system comprising: a first high-voltage power supply; a second high-voltage power supply; a power path provided between the first high-voltage power supply and the second high-voltage power supply; a switch unit provided in the power path; a first conductive path provided between the first high-voltage power supply and the switch unit; a second conductive path provided between the second high-voltage power supply and the switch unit; a first high-voltage load electrically connected to the first conductive path; a first low-voltage load connected to the first conductive path via a first step-down circuit; a second high-voltage load electrically connected to the second conductive path; and a second low-voltage load connected to the second conductive path via a second step-down circuit, wherein the control device includes a control unit for controlling the switch unit, and the control unit, while controlling the switch unit to the ON state, determines whether at least one of the voltage of the power path, the current flowing through the switch unit, and the temperature of the switch unit has become abnormal, and switches the switch unit to the OFF state if it determines that it has become abnormal.
[0007] According to the technology disclosed herein, even if a high-voltage power supply is lost, it becomes easier to continue driving high-voltage loads and low-voltage loads using power obtained by stepping down the output voltage of the high-voltage power supply.
[0008] Figure 1 is a configuration diagram of an in-vehicle system including an in-vehicle control device according to the first embodiment. Figure 2 is a flowchart showing the processing flow performed by the anomaly detection unit 51 of the first embodiment. Figure 3 is a flowchart showing the processing flow performed by the anomaly detection unit 52 of the first embodiment. Figure 4 is a flowchart showing the processing flow performed by the anomaly detection unit 53 of the first embodiment. Figure 5 is a flowchart showing the processing flow performed by the anomaly detection unit 54 of the first embodiment. Figure 6 is a flowchart showing the first processing flow performed by the main control unit of the first embodiment. Figure 7 is a flowchart showing the second processing flow performed by the main control unit of the first embodiment. Figure 8 is a configuration diagram of an in-vehicle system including an in-vehicle control device according to the second embodiment. Figure 9 is a flowchart showing the processing flow performed by the anomaly detection unit 251 of the second embodiment. Figure 10 is a configuration diagram of an in-vehicle system including an in-vehicle control device according to the third embodiment. Figure 11 is a flowchart showing the processing flow performed by the anomaly detection unit 351 of the third embodiment. Figure 12 is a configuration diagram of an in-vehicle system including an in-vehicle control device according to the fourth embodiment. Figure 13 is a flowchart showing the processing flow performed by the anomaly detection unit 453 of the fourth embodiment. Figure 14 is a flowchart showing the processing flow performed by the anomaly detection unit 454 of the fourth embodiment.
[0009] [Description of Embodiments of the Disclosure] First, embodiments of the Disclosure will be listed and described.
[0010] [1] An in-vehicle control device included in an in-vehicle system comprising: a first high-voltage power supply; a second high-voltage power supply; a power path provided between the first high-voltage power supply and the second high-voltage power supply; a switch unit provided in the power path; a first conductive path provided between the first high-voltage power supply and the switch unit; a second conductive path provided between the second high-voltage power supply and the switch unit; a first high-voltage load electrically connected to the first conductive path; a first low-voltage load connected to the first conductive path via a first step-down circuit; a second high-voltage load electrically connected to the second conductive path; and a second low-voltage load connected to the second conductive path via a second step-down circuit, wherein the control unit controls the switch unit to the ON state, determines whether at least one of the voltage of the power path, the current flowing through the switch unit, and the temperature of the switch unit has become abnormal, and switches the switch unit to the OFF state if it determines that it has become abnormal.
[0011] If the first or second high-voltage power supply fails, abnormalities will occur in the voltage of the power line, the current flowing through the switch, and the temperature of the switch. The control unit detects these abnormalities and switches the switch to the off state. Therefore, for example, if the first high-voltage power supply fails and the switch is turned off, power supply from the second high-voltage power supply to the second high-voltage load and the second low-voltage load can continue. Also, if the second high-voltage power supply fails and the switch is turned off, power supply from the first high-voltage power supply to the first high-voltage load and the first low-voltage load can continue.
[0012] [2] The in-vehicle control device according to [1], wherein the first step-down circuit performs a first step-down operation to output a voltage input from the first conductive path to the first low-voltage load side, the second step-down circuit performs a second step-down operation to output a voltage input from the second conductive path to the second low-voltage load side, and the control unit stops the first step-down circuit when it determines that the output voltage of the first step-down circuit has become equal to or greater than a first overvoltage threshold while the first step-down circuit is performing the first step-down operation, and stops the second step-down circuit when it determines that the output voltage of the second step-down circuit has become equal to or greater than a second overvoltage threshold while the second step-down circuit is performing the second step-down operation.
[0013] The above-described in-vehicle control device can shut down the first step-down circuit when the output voltage of the first step-down circuit exceeds the first overvoltage threshold. Furthermore, the above-described in-vehicle control device can shut down the second step-down circuit when the output voltage of the second step-down circuit exceeds the second overvoltage threshold.
[0014] [3] The in-vehicle control device according to [1] or [2], wherein the first step-down circuit performs a first step-down operation to output a voltage input from the first conductive path to the first low-voltage load side, the second step-down circuit performs a second step-down operation to output a voltage input from the second conductive path to the second low-voltage load side, and the control unit stops the first step-down circuit when it determines that the output current of the first step-down circuit has become equal to or greater than a first overcurrent threshold while the first step-down circuit is performing the first step-down operation, and stops the second step-down circuit when it determines that the output current of the second step-down circuit has become equal to or greater than a second overcurrent threshold while the second step-down circuit is performing the second step-down operation.
[0015] The above-described in-vehicle control device can stop the first step-down circuit when the output current of the first step-down circuit exceeds a first overcurrent threshold, thereby preventing overcurrent from being supplied to the first low-voltage load. Furthermore, the above-described in-vehicle control device can stop the second step-down circuit when the output current of the second step-down circuit exceeds a second overcurrent threshold, thereby preventing overcurrent from being supplied to the second low-voltage load.
[0016] [4] The control unit switches the switch unit to the off state, and after a predetermined time has elapsed, it returns the switch unit to the on state, determines again whether or not there is an abnormality, and if it determines that there is an abnormality, switches the switch unit to the off state. The in-vehicle control device according to any one of [1] to [3].
[0017] The above-mentioned in-vehicle control device can switch the switch back to the ON state after a predetermined time has elapsed since the switch was turned OFF. Furthermore, if the abnormal condition persists even after the switch has been turned ON, the in-vehicle control device can switch the switch back to the OFF state once more.
[0018] [5] The control unit, after switching the switch unit to the off state, determines whether the potential difference across the switch unit has fallen below a threshold, and if it determines that it has fallen below a threshold, returns the switch unit to the on state. The in-vehicle control device according to any one of [1] to [3].
[0019] When the switch is in the off state, if the first high-voltage power supply or the second high-voltage power supply is in a failure state, the potential difference across the switch becomes large, and if the first high-voltage power supply and the second high-voltage power supply are not in a failure state, the potential difference across the switch becomes small. After switching the switch to the off state, the in-vehicle control device determines that the potential difference across the switch has fallen below a threshold, and can then consider that the first high-voltage power supply and the second high-voltage power supply are not in a failure state, and can return the switch to the on state.
[0020] [Details of Embodiments of the Disclosure] 1. First Embodiment 1-1. Diagram 1 of the configuration of the in-vehicle system 1 shows an in-vehicle system 1 including an in-vehicle control device 40 of the first embodiment. The in-vehicle system 1 is a system mounted on a vehicle. The in-vehicle system 1 comprises a first high-voltage power supply 11, a second high-voltage power supply 12, a power line 13, a switch unit 14, a first conductive line 15, a second conductive line 16, a first high-voltage load 21, a first low-voltage load 22, a first step-down circuit 23, a second high-voltage load 31, a second low-voltage load 32, and a second step-down circuit 33.
[0021] The first high-voltage power supply 11 is a DC power supply that outputs a high voltage. In this embodiment, the first high-voltage power supply 11 includes an alternator 11A, a first battery 11B, and a voltage conversion unit 11C. The voltage conversion unit 11C boosts or lowers the voltage input from the alternator 11A side or the first battery 11B side and outputs it to the power line 13.
[0022] The second high-voltage power supply 12 is a DC power supply that outputs a high voltage. The output voltage of the second high-voltage power supply 12 may be the same as the output voltage of the first high-voltage power supply 11, may be lower than the output voltage of the first high-voltage power supply 11, or may be higher than the output voltage of the first high-voltage power supply 11. In this embodiment, the second high-voltage power supply 12 includes a second battery 12A.
[0023] The power line 13 is provided between the first high-voltage power supply 11 and the second high-voltage power supply 12. One end of the power line 13 is electrically connected to the first high-voltage power supply 11, and the output voltage of the first high-voltage power supply 11 (specifically, the output voltage of the voltage conversion unit 11C) is applied to it. The other end of the power line 13 is electrically connected to the second high-voltage power supply 12, and the output voltage of the second high-voltage power supply 12 (specifically, the output voltage of the second battery 12A) is applied to it.
[0024] The switch unit 14 is provided in the power line 13. The switch unit 14 switches between an ON state, which allows bidirectional current flow through it, and an OFF state, which blocks bidirectional current flow through it.
[0025] The first conductive path 15 is provided between the first high-voltage power supply 11 and the switch unit 14. One end of the first conductive path 15 is electrically connected to the first high-voltage power supply 11. The other end of the first conductive path 15 is electrically connected to one end of the switch unit 14.
[0026] The second conductive circuit 16 is provided between the second high-voltage power supply 12 and the switch unit 14. One end of the second conductive circuit 16 is electrically connected to the second high-voltage power supply 12. The other end of the second conductive circuit 16 is electrically connected to the other end of the switch unit 14.
[0027] The first high-voltage load 21 is electrically connected to the first conductive path 15. The first low-voltage load 22 is electrically connected to the first conductive path 15 via the first step-down circuit 23. The first step-down circuit 23 is provided between the first conductive path 15 and the first low-voltage load 22. The first step-down circuit 23 performs a first step-down operation, which steps down the voltage input from the first conductive path 15 and outputs it to the first low-voltage load 22.
[0028] The second high-voltage load 31 is electrically connected to the second conductive path 16. The second low-voltage load 32 is electrically connected to the second conductive path 16 via the second step-down circuit 33. The second step-down circuit 33 is provided between the second conductive path 16 and the second low-voltage load 32. The second step-down circuit 33 performs a second step-down operation, stepping down the voltage input from the second conductive path 16 and outputting it to the second low-voltage load 32.
[0029] 1-2. Configuration of the On-board Control Device 40 The on-board control device 40 includes the first step-down circuit 23 and the second step-down circuit 33 described above. Furthermore, the on-board control device 40 includes voltage detection units 41, 42, 43, 44, a main control unit 50, and abnormality detection units 51, 52, 53, 54. The main control unit 50 and the abnormality detection units 51, 52, 53, 54 are examples of control units.
[0030] Voltage detection unit 41 detects the voltage of the first conductive path 15. Voltage detection unit 42 detects the voltage of the second conductive path 16. Voltage detection unit 43 detects the voltage of the third conductive path 17, which is provided between the first step-down circuit 23 and the first low-voltage load 22. In other words, voltage detection unit 43 detects the output voltage of the first step-down circuit 23 when it is performing the first step-down operation. Voltage detection unit 44 detects the voltage of the fourth conductive path 18, which is provided between the second step-down circuit 33 and the second low-voltage load 32. In other words, voltage detection unit 44 detects the output voltage of the second step-down circuit 33 when it is performing the second step-down operation. Voltage detection units 41, 42, 43, and 44 are configured, for example, by known voltage detection circuits.
[0031] The main control unit 50 controls the switch unit 14, the first step-down circuit 23, and the second step-down circuit 33. The main control unit 50 is composed of, for example, a microcomputer. The main control unit 50 also includes, for example, a processor such as a CPU, and memory such as ROM or RAM.
[0032] In the normal state, the main control unit 50 controls the switch unit 14 to the ON state, causing the first step-down circuit 23 to perform the first step-down operation and the second step-down circuit 33 to perform the second step-down operation. As a result, power is supplied from the first high-voltage power supply 11 and the second high-voltage power supply 12 to the first high-voltage load 21 and the second high-voltage load 31. In addition, the power stepped down by the first step-down circuit 23 is supplied to the first low-voltage load 22. The power stepped down by the second step-down circuit 33 is supplied to the second low-voltage load 32.
[0033] 1-3. The abnormality detection unit 51 of the abnormality detection units 51, 52, 53, and 54 determines whether the voltage of the first conductive path 15 is abnormal. The abnormality detection unit 51 identifies the voltage of the first conductive path 15 based on the output value of the voltage detection unit 41. The abnormality detection unit 51 performs the processing shown in Figure 2, for example. In step S11, the abnormality detection unit 51 determines whether the voltage of the first conductive path 15 has fallen below the first threshold voltage. The first threshold voltage is a value of 0V or greater. If the abnormality detection unit 51 determines that the voltage of the first conductive path 15 is not below the first threshold voltage (No in step S11), it returns to step S11. In other words, the abnormality detection unit 51 repeatedly performs the processing in step S11 until it determines that the voltage of the first conductive path 15 is below the first threshold voltage. If the abnormality detection unit 51 determines that the voltage of the first conductive path 15 has fallen below the first threshold voltage (Yes in step S11), it switches the switch unit 14 to the OFF state in step S12, regardless of the control state of the main control unit 50. This allows power to be supplied from the second high-voltage power supply 12 to the second high-voltage load 31 and the second low-voltage load 32 even if the first high-voltage power supply 11 is lost. Also, even if the second high-voltage power supply 12 is lost, power can be supplied from the first high-voltage power supply 11 to the first high-voltage load 21 and the first low-voltage load 22.
[0034] The abnormality detection unit 52 determines whether the voltage of the second conductive path 16 is abnormal. The abnormality detection unit 52 identifies the voltage of the second conductive path 16 based on the output value of the voltage detection unit 42. The abnormality detection unit 52 performs the processing shown in Figure 3, for example. In step S21, the abnormality detection unit 52 determines whether the voltage of the second conductive path 16 has fallen below the second threshold voltage. The second threshold voltage is a value of 0V or greater. The second threshold voltage may be the same as or different from the first threshold voltage. If the abnormality detection unit 52 determines that the voltage of the second conductive path 16 is not below the second threshold voltage (No in step S21), it returns to step S21. In other words, the abnormality detection unit 52 repeatedly performs the processing in step S21 until it determines that the voltage of the second conductive path 16 is below the second threshold voltage. If the abnormality detection unit 52 determines that the voltage of the second conductive path 16 has fallen below the second threshold voltage (Yes in step S21), it switches the switch unit 14 to the OFF state in step S22, regardless of the control state of the main control unit 50. This allows power to be supplied from the second high-voltage power supply 12 to the second high-voltage load 31 and the second low-voltage load 32 even if the first high-voltage power supply 11 is lost. Also, even if the second high-voltage power supply 12 is lost, power can be supplied from the first high-voltage power supply 11 to the first high-voltage load 21 and the first low-voltage load 22.
[0035] The abnormality detection unit 53 determines whether the voltage of the third conductive path 17 is overvoltage. In other words, the abnormality detection unit 53 determines whether the output voltage of the first step-down circuit 23, which is in the state of performing the first step-down operation, is overvoltage. The abnormality detection unit 53 identifies the voltage of the third conductive path 17 based on the output value of the voltage detection unit 43. The abnormality detection unit 53 performs the processing shown in Figure 4, for example. In step S31, the abnormality detection unit 53 determines whether the voltage of the third conductive path 17 has become greater than or equal to the first overvoltage threshold. The first overvoltage threshold is a value greater than 0V. If the abnormality detection unit 53 determines that the voltage of the third conductive path 17 is not greater than or equal to the first overvoltage threshold (No in step S31), it returns to step S31. In other words, the abnormality detection unit 53 repeatedly performs the processing in step S31 until it determines that the voltage of the third conductive path 17 is greater than or equal to the first overvoltage threshold. If the abnormality detection unit 53 determines that the voltage of the third conductive path 17 has exceeded the first overvoltage threshold (Yes in step S31), it stops the operation of the first step-down circuit 23 in step S32, regardless of the control state of the main control unit 50. This prevents overvoltage from being applied to the first low-voltage load 22.
[0036] The abnormality detection unit 54 determines whether the voltage of the fourth conductive path 18 is overvoltage. In other words, the abnormality detection unit 54 determines whether the output voltage of the second step-down circuit 33, which is performing the second step-down operation, is overvoltage. The abnormality detection unit 54 identifies the voltage of the fourth conductive path 18 based on the output value of the voltage detection unit 44. The abnormality detection unit 54 performs the processing shown in Figure 5, for example. In step S41, the abnormality detection unit 54 determines whether the voltage of the fourth conductive path 18 has become greater than or equal to the second overvoltage threshold. The second overvoltage threshold is a value greater than 0V. The second overvoltage threshold may be the same as or different from the first overvoltage threshold. If the abnormality detection unit 54 determines that the voltage of the fourth conductive path 18 is not greater than or equal to the second overvoltage threshold (No in step S41), it returns to step S41. In other words, the abnormality detection unit 54 repeatedly performs the processing in step S41 until it determines that the voltage of the fourth conductive path 18 is greater than or equal to the second overvoltage threshold. If the abnormality detection unit 54 determines that the voltage of the fourth conductive path 18 has exceeded the second overvoltage threshold (Yes in step S41), it stops the operation of the second step-down circuit 33 in step S42, regardless of the control state of the main control unit 50. This prevents overvoltage from being applied to the second low-voltage load 32.
[0037] The anomaly detection units 51, 52, 53, and 54 are composed of hardware circuits such as comparators.
[0038] 1-4. Return Operation of Switch Unit 14 1-4-1. First Example The main control unit 50 returns the switch unit 14 to the ON state after a predetermined time has elapsed since the switch unit 14 was switched to the OFF state by the abnormality detection units 51 and 52. The main control unit 50 performs the process shown in Figure 6, for example. In step S51, the main control unit 50 determines whether the switch unit 14 has switched to the OFF state while it is controlled to be in the ON state. The main control unit 50 determines whether the switch unit 14 has switched to the OFF state based on signals output from the abnormality detection units 51 and 52, for example. Specifically, the main control unit 50 determines that the switch unit 14 has switched to the OFF state when an OFF signal is output to the switch unit 14 from the abnormality detection unit 51 or the abnormality detection unit 52.
[0039] The main control unit 50 repeatedly performs the process in step S51 until it determines that the switch unit 14 has been switched to the off state. If the main control unit 50 determines that the switch unit 14 has been switched to the off state (Yes in step S51), it determines in step S52 whether a predetermined time has elapsed.
[0040] The main control unit 50 repeatedly performs the process in step S52 until it determines that a predetermined time has elapsed. When the main control unit 50 determines that a predetermined time has elapsed (Yes in step S52), in step S53, it releases the control state of the abnormality detection units 51 and 52 and switches the switch unit 14 to the ON state.
[0041] After the switch unit 14 returns to the ON state, the abnormality detection unit 51 again determines whether the voltage of the first conductive path 15 is below the first threshold voltage, and if it determines that it is below the first threshold voltage, it switches the switch unit 14 to the OFF state. Also, after the switch unit 14 returns to the ON state, the abnormality detection unit 52 again determines whether the voltage of the second conductive path 16 is below the second threshold voltage, and if it determines that it is below the second threshold voltage, it switches the switch unit 14 to the OFF state.
[0042] With this configuration, the in-vehicle control device 40 can switch the switch unit 14 back to the ON state after a predetermined time has elapsed since switching it to the OFF state. Furthermore, if the abnormal condition persists even after the switch unit 14 has been switched back to the ON state, the in-vehicle control device 40 can switch the switch unit 14 back to the OFF state once more.
[0043] 1-4-2. Second Example After the switch unit 14 is switched to the off state by the abnormality detection units 51 and 52, the main control unit 50 returns the switch unit 14 to the on state when the potential difference across both ends of the switch unit 14 becomes less than or equal to the threshold value. The main control unit 50 performs, for example, the process shown in FIG. 7. In step S61, the main control unit 50 determines whether the switch unit 14 has been switched to the off state while the switch unit 14 is being controlled in the on state. The main control unit 50 determines whether the switch unit 14 has been switched to the off state based on, for example, the signals output from the abnormality detection units 51 and 52. Specifically, the main control unit 50 determines that the switch unit 14 has been switched to the off state when an off signal is output to the switch unit 14 from either the abnormality detection unit 51 or the abnormality detection unit 52.
[0044] The main control unit 50 repeats the process of step S61 until it determines that the switch unit 14 has been switched to the off state. When the main control unit 50 determines that the switch unit 14 has been switched to the off state (Yes in step S61), in step S62, it determines whether the potential difference across both ends of the switch unit 14 is less than or equal to the threshold value.
[0045] The main control unit 50 repeats the process of step S62 until it determines that the potential difference across both ends of the switch unit 14 is less than or equal to the threshold value. When the main control unit 50 determines that the potential difference across both ends of the switch unit 14 is less than or equal to the threshold value (Yes in step S62), in step S63, it releases the control state of the abnormality detection units 51 and 52 and switches the switch unit 14 to the on state.
[0046] After the switch unit 14 returns to the on state, the abnormality detection unit 51 determines again whether the voltage of the first conductive path 15 is less than or equal to the first threshold voltage, and when it determines that the voltage is less than or equal to the first threshold voltage, it switches the switch unit 14 to the off state. Also, after the switch unit 14 returns to the on state, the abnormality detection unit 52 determines again whether the voltage of the second conductive path 16 is less than or equal to the second threshold voltage, and when it determines that the voltage is less than or equal to the second threshold voltage, it switches the switch unit 14 to the off state.
[0047] According to this configuration, after the in-vehicle control device 40 switches the switch unit 14 to the off state, if it determines that the potential difference across both ends of the switch unit 14 has become less than or equal to the threshold value, it considers that the first high-voltage power source 11 and the second high-voltage power source 12 are not in a defective state, and can return the switch unit 14 to the on state. Further, if the abnormal state continues even after the in-vehicle control device 40 returns the switch unit 14 to the on state, it can switch the switch unit 14 to the off state again.
[0048] 2. Second Embodiment In the second embodiment, a configuration for switching the switch unit 14 to the off state when the current flowing through the switch unit 14 becomes abnormal will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.
[0049] FIG. 8 shows an in-vehicle system 201 including the in-vehicle control device 240 of the second embodiment. The in-vehicle system 201 includes an in-vehicle control device 240 instead of the in-vehicle control device 40 described in the first embodiment. The in-vehicle control device 240 includes an abnormality detection unit 251 instead of the abnormality detection units 51 and 52 described in the first embodiment. Further, the in-vehicle control device 240 includes a current detection unit 245.
[0050] The current detection unit 245 detects the current flowing through the switch unit 14. The current detection unit 245 is configured by, for example, a known current sensor.
[0051] The abnormality detection unit 251 determines whether the current value flowing through the switch unit 14 is abnormal. The abnormality detection unit 251 identifies the current value flowing through the switch unit 14 based on the output value of the current detection unit 245. The abnormality detection unit 251 performs the processing shown in Figure 9, for example. In step S211, the abnormality detection unit 251 determines whether the current value flowing through the switch unit 14 has become greater than or equal to the threshold current. The threshold current is a value greater than 0A. If the abnormality detection unit 251 determines that the current value flowing through the switch unit 14 is not greater than or equal to the threshold current (No in step S211), it returns to step S211. In other words, the abnormality detection unit 251 repeatedly performs the processing in step S211 until it determines that the current value flowing through the switch unit 14 is greater than or equal to the threshold current. If the abnormality detection unit 251 determines that the current value flowing through the switch unit 14 has become greater than or equal to the threshold current (Yes in step S211), it switches the switch unit 14 to the off state in step S212, regardless of the control state of the main control unit 50. As a result, even if the first high-voltage power supply 11 is lost, power can continue to be supplied from the second high-voltage power supply 12 to the second high-voltage load 31 and the second low-voltage load 32. Also, even if the second high-voltage power supply 12 is lost, power can continue to be supplied from the first high-voltage power supply 11 to the first high-voltage load 21 and the first low-voltage load 22.
[0052] 3. Third Embodiment In the third embodiment, a configuration will be described in which the switch unit 14 is switched to the OFF state when the temperature of the switch unit 14 becomes abnormal. In the third embodiment, the same reference numerals are used for the same components as in the first embodiment, and detailed explanations will be omitted.
[0053] Figure 10 shows an in-vehicle system 301 including an in-vehicle control device 340 of the third embodiment. The in-vehicle system 301 includes an in-vehicle control device 340 instead of the in-vehicle control device 40 described in the first embodiment. The in-vehicle control device 340 includes an abnormality detection unit 351 instead of the abnormality detection units 51 and 52 described in the first embodiment. Furthermore, the in-vehicle control device 340 includes a temperature detection unit 345.
[0054] The temperature detection unit 345 detects the temperature of the switch unit 14. The temperature detection unit 345 is composed of, for example, a known temperature sensor.
[0055] The abnormality detection unit 351 determines whether the temperature of the switch unit 14 is abnormal. The abnormality detection unit 351 identifies the temperature of the switch unit 14 based on the output value of the temperature detection unit 345. The abnormality detection unit 351 performs the processing shown in Figure 11, for example. In step S311, the abnormality detection unit 351 determines whether the temperature of the switch unit 14 has risen above the threshold temperature. If the abnormality detection unit 351 determines that the temperature of the switch unit 14 is not above the threshold temperature (No in step S311), it returns to step S311. In other words, the abnormality detection unit 351 repeatedly performs the processing in step S311 until it determines that the temperature of the switch unit 14 is above the threshold temperature. If the abnormality detection unit 351 determines that the temperature of the switch unit 14 has risen above the threshold temperature (Yes in step S311), it switches the switch unit 14 to the off state in step S312, regardless of the control state of the main control unit 50. As a result, even if the first high-voltage power supply 11 is lost, power can continue to be supplied from the second high-voltage power supply 12 to the second high-voltage load 31 and the second low-voltage load 32. Also, even if the second high-voltage power supply 12 is lost, power can continue to be supplied from the first high-voltage power supply 11 to the first high-voltage load 21 and the first low-voltage load 22.
[0056] 4. Fourth Embodiment In the fourth embodiment, a configuration will be described in which the first step-down circuit 23 is stopped when the output current of the first step-down circuit 23 becomes overcurrent, and the second step-down circuit 33 is stopped when the output current of the second step-down circuit 33 becomes overcurrent. In the fourth embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations will be omitted.
[0057] Figure 12 shows an in-vehicle system 401 including an in-vehicle control device 440 of the fourth embodiment. The in-vehicle system 401 includes an in-vehicle control device 440 instead of the in-vehicle control device 40 described in the first embodiment. The in-vehicle control device 440 includes current detection units 443 and 444 instead of voltage detection units 43 and 44 described in the first embodiment. The in-vehicle control device 440 also includes abnormality detection units 453 and 454 instead of abnormality detection units 53 and 54 described in the first embodiment.
[0058] The current detection unit 443 detects the current value flowing through the third conductive path 17. The current detection unit 443 detects the output current of the first step-down circuit 23 when it is performing the first step-down operation. The current detection unit 443 is configured, for example, by a known current sensor.
[0059] The current detection unit 444 detects the current value flowing through the fourth conductive path 18. The current detection unit 444 also detects the output current of the second step-down circuit 33 when it is performing the second step-down operation. The current detection unit 444 is composed of, for example, a known current sensor.
[0060] The abnormality detection unit 453 determines whether the output current of the first step-down circuit 23, which is performing the first step-down operation, is an overcurrent. In other words, the abnormality detection unit 453 determines whether the output current of the first step-down circuit 23, which is performing the first step-down operation, is an overcurrent. The abnormality detection unit 453 identifies the output current of the first step-down circuit 23 based on the output value of the current detection unit 443. The abnormality detection unit 453 performs the processing shown in Figure 13, for example. In step S431, the abnormality detection unit 453 determines whether the output current of the first step-down circuit 23 has become greater than or equal to the first overcurrent threshold. The first overvoltage threshold is a value greater than 0V. If the abnormality detection unit 453 determines that the output current of the first step-down circuit 23 is not greater than or equal to the first overcurrent threshold (No in step S431), it returns to step S431. In other words, the abnormality detection unit 453 repeatedly performs the processing in step S431 until it determines that the output current of the first step-down circuit 23 is greater than or equal to the first overcurrent threshold. If the abnormality detection unit 453 determines that the output current of the first step-down circuit 23 has exceeded the first overcurrent threshold (Yes in step S431), it stops the operation of the first step-down circuit 23 in step S432, regardless of the control state of the main control unit 50. This prevents overcurrent from flowing through the third conductive path 17 and the first low-voltage load 22.
[0061] The abnormality detection unit 454 determines whether the output current of the second step-down circuit 33, which is performing the second step-down operation, is an overcurrent. In other words, the abnormality detection unit 454 determines whether the output current of the second step-down circuit 33, which is performing the second step-down operation, is an overcurrent. The abnormality detection unit 454 identifies the output current of the second step-down circuit 33 based on the output value of the current detection unit 444. The abnormality detection unit 454 performs the processing shown in Figure 14, for example. In step S441, the abnormality detection unit 454 determines whether the output current of the second step-down circuit 33 has become greater than or equal to the second overcurrent threshold. The second overvoltage threshold is a value greater than 0V. The second overcurrent threshold may be the same as or different from the first overcurrent threshold. If the abnormality detection unit 454 determines that the output current of the second step-down circuit 33 is not greater than or equal to the second overcurrent threshold (No in step S441), it returns to step S441. In other words, the abnormality detection unit 454 repeatedly performs the process in step S441 until it determines that the output current of the second step-down circuit 33 is equal to or greater than the second overcurrent threshold. When the abnormality detection unit 454 determines that the output current of the second step-down circuit 33 is equal to or greater than the second overcurrent threshold (Yes in step S441), it stops the operation of the second step-down circuit 33 in step S442, regardless of the control state of the main control unit 50. This prevents overcurrent from flowing through the fourth conductive path 18 and the second low-voltage load 32.
[0062] The anomaly detection units 453 and 454 are composed of hardware circuits such as comparators.
[0063] <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict the original. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows.
[0064] In the embodiments described above, examples were given in which the main control unit and the anomaly detection unit are configured by separate control circuits. However, the main control unit and the anomaly detection unit may be configured by the same control circuit. For example, the main control unit and the anomaly detection unit may be configured by the same microcomputer.
[0065] In the above embodiments, the in-vehicle control device was configured to include a first step-down circuit and a second step-down circuit. However, the in-vehicle control device may also be configured not to include a first step-down circuit and a second step-down circuit.
[0066] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included.
[0067] 1...In-vehicle system 11...First high-voltage power supply 11A...Alternator 11B...First battery 11C...Voltage conversion unit 12...Second high-voltage power supply 12A...Second battery 13...Power line 14...Switch unit 15...First conductive line 16...Second conductive line 17...Third conductive line 18...Fourth conductive line 21...First high-voltage load 22...First low-voltage load 23...First step-down circuit 31...Second high-voltage load 32...Second low-voltage load 33...Second step-down circuit 40...In-vehicle control device 41...Voltage detection unit 42...Voltage detection unit 43...Voltage detection unit 44...Voltage detection unit 50...Main control unit (control unit) 51...Anomaly detection unit (control unit) 52...Anomaly detection unit (control unit) 53...Anomaly detection unit (control unit) 54...Anomaly detection unit (control unit) 201...In-vehicle system 240...In-vehicle control device 245...Current detection unit 251...Anomaly detection unit (control unit) 301...In-vehicle system 340...In-vehicle control device 345...Temperature detection unit 351...Anomaly detection unit (control unit) 401...In-vehicle system 440...In-vehicle control device 443...Current detection unit 444...Current detection unit 453...Anomaly detection unit (control unit) 454...Anomaly detection unit (control unit)
Claims
1. An in-vehicle control device included in an in-vehicle system comprising: a first high-voltage power supply; a second high-voltage power supply; a power path provided between the first high-voltage power supply and the second high-voltage power supply; a switch unit provided in the power path; a first conductive path provided between the first high-voltage power supply and the switch unit; a second conductive path provided between the second high-voltage power supply and the switch unit; a first high-voltage load electrically connected to the first conductive path; a first low-voltage load connected to the first conductive path via a first step-down circuit; a second high-voltage load electrically connected to the second conductive path; and a second low-voltage load connected to the second conductive path via a second step-down circuit, wherein the control unit controls the switch unit to the ON state, determines whether at least one of the voltage of the power path, the current flowing through the switch unit, and the temperature of the switch unit has become abnormal, and switches the switch unit to the OFF state if it determines that it has become abnormal.
2. The in-vehicle control device according to claim 1, wherein the first step-down circuit performs a first step-down operation to output a voltage input from the first conductive path to the first low-voltage load side, the second step-down circuit performs a second step-down operation to output a voltage input from the second conductive path to the second low-voltage load side, and the control unit stops the first step-down circuit when it determines that the output voltage of the first step-down circuit is equal to or greater than a first overvoltage threshold while the first step-down circuit is performing the first step-down operation, and stops the second step-down circuit when it determines that the output voltage of the second step-down circuit is equal to or greater than a second overvoltage threshold while the second step-down circuit is performing the second step-down operation.
3. The in-vehicle control device according to claim 1, wherein the first step-down circuit performs a first step-down operation, outputting a voltage input from the first conductive path to the first low-voltage load side; the second step-down circuit performs a second step-down operation, outputting a voltage input from the second conductive path to the second low-voltage load side; the control unit stops the first step-down circuit when it determines that the output current of the first step-down circuit is equal to or greater than a first overcurrent threshold while the first step-down circuit is performing the first step-down operation; and stops the second step-down circuit when it determines that the output current of the second step-down circuit is equal to or greater than a second overcurrent threshold while the second step-down circuit is performing the second step-down operation.
4. The in-vehicle control device according to any one of claims 1 to 3, wherein the control unit switches the switch unit to the off state, and after a predetermined time has elapsed, it returns the switch unit to the on state, determines again whether or not there is an abnormality, and if it determines that there is an abnormality, it switches the switch unit to the off state.
5. The in-vehicle control device according to any one of claims 1 to 3, wherein the control unit, after switching the switch unit to the off state, determines whether the potential difference across both ends of the switch unit has fallen below a threshold, and if it determines that it has fallen below a threshold, returns the switch unit to the on state.