Abnormality detection device

Abstract

This abnormality detection device (30) comprises an abnormality detection unit (34). The abnormality detection unit (34) detects an open failure of at least one among a first power supply unit (11) and a load (14) on the basis of the amount of variation in the value of current flowing through each of at least two conductive paths among: a first conductive path (21) provided between the first power supply unit (11) and a connection point (15); a second conductive path (22) provided between a second power supply unit (12) and the connection point (15); and a third conductive path (23) provided between the load (14) and the connection point (15).

Description

Abnormal detection device

[0001] The present disclosure relates to an abnormal detection device.

[0002] In the power supply system disclosed in Patent Document 1, during charging of the first battery by the second battery and the DC / DC converter, or during execution of open fault detection control for repeatedly charging and discharging the first battery by the DC / DC converter, the ECU determines whether the absolute value of the current value (battery current value) input to and output from the first battery is continuously below a fault threshold for a certain period of time. When the condition that the absolute value of the battery current value is continuously below the fault threshold for a certain period of time is satisfied, the ECU determines that an open fault has occurred in the first battery.

[0003] Japanese Patent Application Laid-Open No. 2023-086278

[0004] In the configuration of Patent Document 1, it is essential to charge the first battery when determining an open fault in the first battery. That is, in the configuration of Patent Document 1, an open fault in the first battery cannot be determined in a state where discharge is possible from both sides of the first battery and the second battery. Further, Patent Document 1 does not describe how to determine an open fault in a load.

[0005] An object of the present disclosure is to provide a technique capable of quickly detecting an open fault in at least one of the first power supply unit and the load in a state where discharge to the load is possible from both the first power supply unit and the second power supply unit.

[0006] An anomaly detection device according to the present disclosure is an anomaly detection device included in an in-vehicle system comprising a first power supply unit, a second power supply unit, a power path provided between the first power supply unit and the second power supply unit, and a load electrically connected to the connection point of the power path, the anomaly detection device comprising an anomaly detection unit for detecting an anomaly, wherein the output voltage of the first power supply unit is higher than the output voltage of the second power supply unit, and the anomaly detection unit detects an open fault in at least one of the first power supply unit and the load based on the amount of change in the current value flowing through at least two conductive paths, which are provided between the first power supply unit and the connection point, the second conductive path provided between the second power supply unit and the connection point, and the third conductive path provided between the load and the connection point.

[0007] According to the technology disclosed herein, an open fault in at least one of the power supply unit and the load can be quickly detected when both the first power supply unit and the second power supply unit are in a state where they can discharge to the load.

[0008] Figure 1 is a configuration diagram of an in-vehicle system including an anomaly detection device of the first embodiment. Figure 2 is a conceptual explanatory diagram showing an in-vehicle system in a state where current is supplied from the first power supply unit to the load. Figure 3 is a conceptual explanatory diagram showing the state of the in-vehicle system when the first power supply unit has an open fault. Figure 4 is a conceptual explanatory diagram showing the state of the in-vehicle system when the load has an open fault. Figure 5 is a flowchart showing the first processing flow for determining an open fault in the first power supply unit in the first embodiment. Figure 6 is a flowchart showing the second processing flow for determining an open fault in the first power supply unit in the first embodiment. Figure 7 is a flowchart showing the first processing flow for determining an open fault in the load in the first embodiment. Figure 8 is a flowchart showing the second processing flow for determining an open fault in the load in the first embodiment. Figure 9 is a configuration diagram of an in-vehicle system including an anomaly detection device of the second embodiment. Figure 10 is a flowchart showing the processing flow for determining an open fault in the first power supply unit in the second embodiment.

[0009] [Description of Embodiments of the Disclosure] First, embodiments of the Disclosure will be listed and described.

[0010] [1] An anomaly detection device included in an in-vehicle system comprising a first power supply unit, a second power supply unit, a power path provided between the first power supply unit and the second power supply unit, and a load electrically connected to the connection point of the power path, comprising an anomaly detection unit for detecting an anomaly, wherein the output voltage of the first power supply unit is higher than the output voltage of the second power supply unit, and the anomaly detection unit detects an open fault in at least one of the first power supply unit and the load based on the amount of change in the current value flowing through each of at least two conductive paths, which are provided between the first power supply unit and the connection point, the second conductive path provided between the second power supply unit and the connection point, and the third conductive path provided between the load and the connection point.

[0011] In a configuration where the output voltage of the first power supply is higher than the output voltage of the second power supply, current flows from the first power supply to the load. In this state, if the first power supply experiences an open fault, the output current from the first power supply decreases, and current flows from the second power supply to the load. If the load experiences an open fault, no current is supplied to the load from either the first or second power supply. By utilizing this phenomenon, the abnormality detection unit can detect an open fault in at least one of the first power supply and the load based on the amount of change in the current value flowing through at least two of the conductive paths, the first conductive path, and the third conductive path.

[0012] [2] The abnormality detection device according to [1], wherein the abnormality detection unit determines that the first power supply unit is open fault when, within a predetermined time, the amount of decrease in the current value flowing through the first conductive path becomes equal to or greater than a first threshold, and the amount of increase in the current value flowing through the second conductive path becomes equal to or greater than a second threshold.

[0013] When the first power supply unit experiences an open fault, the output current from the first power supply unit decreases, and current flows from the second power supply unit to the load. By utilizing this phenomenon, the abnormality detection unit can determine that the first power supply unit has an open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path exceeds a first threshold, and the increase in the current value flowing through the second conductive path exceeds a second threshold.

[0014] [3] The abnormality detection device according to [1], wherein the abnormality detection unit determines that the first power supply unit is open fault when, within a predetermined time, the amount of decrease in the current value flowing through the first conductive path is equal to or greater than a first threshold, and the amount of fluctuation in the current value flowing through the third conductive path is less than or equal to a third threshold which is smaller than the first threshold.

[0015] When the first power supply unit experiences an open fault, the output current from the first power supply unit decreases, while the current supplied to the load is maintained by the current from the second power supply unit. Utilizing this phenomenon, the abnormality detection unit can determine that the first power supply unit has an open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path is greater than or equal to a first threshold, and the fluctuation in the current value flowing through the third conductive path is less than or equal to a third threshold (which is smaller than the first threshold).

[0016] [4] The abnormality detection device according to any one of [1] to [3], wherein the abnormality detection unit determines that the load is an open fault when, while the vehicle's start switch remains ON, the decrease in the current value flowing through the first conductive path becomes equal to or greater than a first threshold for a predetermined time, and the current value flowing through the second conductive path does not increase.

[0017] When a load experiences an open fault, the output current from the first power supply unit stops, and no current is supplied to the load from the second power supply unit either. Utilizing this phenomenon, the abnormality detection unit can determine that the load has an open fault if, within a predetermined time, the decrease in the current flowing through the first conductive path exceeds a first threshold, and the current flowing through the second conductive path does not increase. Furthermore, by requiring the vehicle's start switch to remain in the ON state, cases where the load would normally stop due to the start switch being turned OFF can be excluded.

[0018] [5] The abnormality detection device according to any one of [1] to [3], wherein the abnormality detection unit determines that the load is an open fault when, while the vehicle's start switch remains ON, the decrease in the current value flowing through the first conductive path becomes greater than or equal to a first threshold, and the decrease in the current value flowing through the third conductive path becomes greater than or equal to a fourth threshold, within a predetermined time.

[0019] When a load experiences an open fault, the output current from the first power supply unit stops, and no current is supplied to the load from the second power supply unit. Utilizing this phenomenon, the abnormality detection unit can determine that the load has an open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path exceeds a first threshold, and the decrease in the current value flowing through the third conductive path exceeds a fourth threshold. Furthermore, by requiring the vehicle's start switch to remain in the ON state, cases where the load normally stops due to the start switch being turned OFF can be excluded.

[0020] [6] An anomaly detection device according to [2], wherein a fourth conductive path is provided between the first conductive path and the second conductive path, a plurality of loads are provided, the third conductive path is provided to correspond individually to each load, and each load is electrically connected to the fourth conductive path via the third conductive path corresponding to itself.

[0021] The abnormality detection unit can detect an open fault in the first power supply unit even in a configuration where multiple loads are connected to the fourth conductive path.

[0022] [7] A fourth conductive path is provided between the first conductive path and the second conductive path, a plurality of loads are provided, the third conductive path is provided to correspond individually to each load, each load is electrically connected to the fourth conductive path via the third conductive path corresponding to itself, the abnormality detection unit determines that the first power supply unit is open fault when, within a predetermined time, the amount of decrease in the current value flowing through the first conductive path is equal to or greater than a first threshold, and the amount of change in the total current value flowing through each of the third conductive paths is equal to or less than a fifth threshold, the fifth threshold is a value smaller than the number of loads multiplied by the first threshold, the abnormality detection device according to [1].

[0023] When the first power supply unit experiences an open fault, the output current from the first power supply unit decreases, while the current supplied to each load is maintained by the current from the second power supply unit. Utilizing this phenomenon, the abnormality detection unit can determine that the first power supply unit has an open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path exceeds a first threshold, and the fluctuation in the total current value flowing through each of the third conductive paths is less than or equal to a fifth threshold.

[0024] [Details of Embodiments of the Disclosure] 1. First Embodiment 1-1. Diagram 1 of the in-vehicle system configuration shows an in-vehicle system 1 including an abnormality detection device 30 of the first embodiment. The in-vehicle system 1 is a system mounted on a vehicle. The in-vehicle system 1 comprises a first power supply unit 11, a second power supply unit 12, a power line 13, and a load 14.

[0025] In this embodiment, the first power supply unit 11 is a power storage unit and is composed of, for example, a battery. The second power supply unit 12 is also a power storage unit in this embodiment and is composed of, for example, a battery. The output voltage of the first power supply unit 11 is higher than the output voltage of the second power supply unit 12. The power line 13 is provided between the first power supply unit 11 and the second power supply unit 12. One end of the power line 13 is electrically connected to the first power supply unit 11, and the other end of the power line 13 is electrically connected to the second power supply unit 12. The load 14 is electrically connected to the connection point 15 of the power line 13.

[0026] The in-vehicle system 1 includes a first conductive path 21, a second conductive path 22, and a third conductive path 23. The first conductive path 21 is provided between the first power supply unit 11 and the connection point 15. The second conductive path 22 is provided between the second power supply unit 12 and the connection point 15. The third conductive path 23 is provided between the load 14 and the connection point 15.

[0027] 1-2. Configuration of the Anomaly Detection Device 30 The anomaly detection device 30 comprises a first current sensor 31, a second current sensor 32, a third current sensor 33, and an anomaly detection unit 34. The first current sensor 31 detects the current flowing through the first conductive path 21. The first current sensor 31 detects the output current of the first power supply unit 11. The second current sensor 32 detects the current flowing through the second conductive path 22. The second current sensor 32 detects the output current of the second power supply unit 12. The third current sensor 33 detects the current flowing through the third conductive path 23. The third current sensor 33 detects the current flowing from the power path 13 side to the load 14 side. Signals indicating the detection results of the first current sensor 31, the second current sensor 32, and the third current sensor 33 are input to the anomaly detection unit 34.

[0028] The anomaly detection unit 34 is configured to include, for example, a microcomputer. The anomaly detection unit 34 includes, for example, a processor such as a CPU, and memory such as ROM or RAM. The anomaly detection unit 34 identifies the current value flowing through the first conductive path 21 based on the signal output from the first current sensor 31. The anomaly detection unit 34 identifies the current value flowing through the second conductive path 22 based on the signal output from the second current sensor 32. The anomaly detection unit 34 identifies the current value flowing through the third conductive path 23 based on the signal output from the third current sensor 33.

[0029] In this embodiment, the load 14 operates when the vehicle's start switch is ON and stops when the start switch is OFF. The load 14 may be configured to operate or stop in response to an external command, for example, or it may be configured to operate when a switch that cuts off the power supply to the load 14 is ON and stop when it is OFF. The start switch may be an ignition switch or a power switch, for example.

[0030] As described above, the output voltage of the first power supply unit 11 is higher than the output voltage of the second power supply unit 12. Therefore, when the vehicle's start switch is ON, a current of, for example, 100A flows from the first power supply unit 11 to the load 14, as shown in Figure 2. At this time, the current values ​​flowing through the first conductive path 21 and the third conductive path 23 are 100A, and the current value flowing through the second conductive path 22 is 0A.

[0031] In the state shown in Figure 2, if the first power supply unit 11 experiences an open fault, the output from the first power supply unit 11 stops, as shown in Figure 3, and a current of 100A flows from the second power supply unit 12 to the load 14. At this time, the current flowing through the first conductive path 21 is 0A, and the current flowing through the second conductive path 22 and the third conductive path 23 is 100A. Here, an open fault is when an electrical path becomes open due to an abnormality such as a broken wire, and the flow of current is interrupted.

[0032] In the state shown in Figure 2, if the load 14 experiences an open fault, no current will be supplied to the load 14 from either the first power supply unit 11 or the second power supply unit 12, as shown in Figure 4. At this time, the current values ​​flowing through the first conductive path 21, the second conductive path 22, and the third conductive path 23 are 0A.

[0033] The abnormality detection unit 34 utilizes the above-described phenomenon to detect an open fault in at least one of the first power supply unit 11 and the load 14 based on the amount of change in the current value flowing through each of at least two of the conductive paths among the first conductive path 21, the second conductive path 22, and the third conductive path 23.

[0034] 1-3. Example 1 of Determining an Open Circuit Fault in the First Power Supply Unit 11 For example, the abnormality detection unit 34 performs the process shown in Figure 5 to determine an open circuit fault in the first power supply unit 11. The abnormality detection unit 34 may perform the process shown in Figure 5 only when the start switch is ON, or it may perform it regardless of the ON / OFF state of the start switch. The abnormality detection unit 34 may also determine the ON / OFF state of the start switch by obtaining an ON / OFF signal indicating the ON / OFF state of the start switch from an external source.

[0035] In step S11 of Figure 5, the abnormality detection unit 34 determines whether, within a predetermined time, the decrease in the current value flowing through the first conductive path 21 is equal to or greater than the first threshold, and the increase in the current value flowing through the second conductive path 22 is equal to or greater than the second threshold. The second threshold may be the same as or different from the first threshold.

[0036] In this specification, "amount" refers to "width" or "ratio." That is, "decrease amount" refers to "decrease width" or "decrease rate." Furthermore, the decrease amount over a predetermined period of time may be, for example, the decrease amount from the start to the end of the predetermined period, or the maximum decrease amount from the start of the predetermined period. The increase amount over a predetermined period of time may be, for example, the increase amount from the start to the end of the predetermined period, or the maximum increase amount from the start of the predetermined period. The current value at the start of the predetermined period may be determined from a single detection result, or it may be an average value such as a moving average.

[0037] If the first power supply unit 11 and the load 14 are not open faults, the current value flowing through the first conductive path 21 is maintained at 100A, and the current value flowing through the second conductive path 22 is maintained at 0A, as shown in Figure 2. In this case, the abnormality detection unit 34 determines No in step S11. If the abnormality detection unit 34 determines No in step S11, it returns to step S11. In other words, the abnormality detection unit 34 repeats the process of step S11 until it determines Yes in step S11.

[0038] If the first power supply unit 11 experiences an open fault, as shown in Figure 3, the current flowing through the first conductive path 21 decreases to 0A, and the current flowing through the second conductive path 22 increases to 100A. As a result, the abnormality detection unit 34 determines "Yes" in step S11. Then, in step S12, the abnormality detection unit 34 determines that the first power supply unit 11 has experienced an open fault.

[0039] Thus, the abnormality detection unit 34 can determine that the first power supply unit 11 has an open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path 21 exceeds a first threshold, and the increase in the current value flowing through the second conductive path 22 exceeds a second threshold. Furthermore, if an open fault is determined solely by the decrease in the current value flowing through the first conductive path 21, the determination takes time in order to exclude cases of temporary current value decreases within the normal range. However, with this configuration, since the first power supply unit 11 is determined to have an open fault when the current value flowing through the second conductive path 22 increases despite the decrease in the current value flowing through the first conductive path 21, an open fault can be determined quickly.

[0040] 1-4. Example 2 of Determining an Open Circuit Fault in the First Power Supply Unit 11 As another example, the abnormality detection unit 34 performs the process shown in Figure 6 to determine an open circuit fault in the first power supply unit 11. The abnormality detection unit 34 may perform the process shown in Figure 6 only when the start switch is ON, or it may perform it regardless of whether the start switch is ON or OFF.

[0041] In step S21 of Figure 6, the abnormality detection unit 34 determines whether, within a predetermined time, the decrease in the current value flowing through the first conductive path 21 is equal to or greater than a first threshold, and whether the fluctuation in the current value flowing through the third conductive path 23 is less than or equal to a third threshold, which is smaller than the first threshold. When the abnormality detection unit 34 determines whether the fluctuation in the current value flowing through the third conductive path 23 is less than or equal to the third threshold, it may also determine whether the current value flowing through the third conductive path 23 has not fluctuated at all. In this case, the abnormality detection unit 34 may determine that there has been virtually no fluctuation if the fluctuation is within 5%.

[0042] If the first power supply unit 11 and the load 14 are not open faults, the current values ​​flowing through the first conductive path 21 and the third conductive path 23 are maintained at 100A, as shown in Figure 2. In this case, the abnormality detection unit 34 determines No in step S21. If the abnormality detection unit 34 determines No in step S21, it returns to step S21. In other words, the abnormality detection unit 34 repeats the process of step S21 until it determines Yes in step S21.

[0043] When the first power supply unit 11 has an open fault, as shown in FIG. 3, the current value flowing through the first conductive path 21 decreases to 0 A, and the current value flowing through the third conductive path 23 is maintained at 100 A. As a result, the abnormality detection unit 34 determines Yes in step S21. Then, the abnormality detection unit 34 determines in step S22 that the first power supply unit 11 has an open fault.

[0044] In this way, when the amount of decrease in the current value flowing through the first conductive path 21 is equal to or greater than the first threshold value and the amount of variation in the current value flowing through the third conductive path 23 is equal to or less than the third threshold value, which is smaller than the first threshold value, within a predetermined time, the abnormality detection unit 34 can determine that the first power supply unit 11 has an open fault. Also, when determining an open fault only based on the decrease in the current value flowing through the first conductive path 21, it takes time for the determination in order to exclude cases of temporary decrease in the current value within the normal range. However, according to this configuration, even though the current value flowing through the first conductive path 21 has decreased, when the current value flowing through the third conductive path 23 does not vary much, it can be determined that the first power supply unit 11 has an open fault, so the open fault can be determined quickly.

[0045] 1-5. Determination example 1 of open fault of load 14 For example, when the start switch of the vehicle is in the on state, the abnormality detection unit 34 determines that the load 14 has an open fault when the amount of decrease in the current value flowing through the first conductive path 21 is equal to or greater than the first threshold value and the current value flowing through the second conductive path 22 has not increased within a predetermined time. Specifically, the abnormality detection unit 34 performs the process shown in FIG. 7. When the start switch is in the on state, the abnormality detection unit 34 starts the process shown in FIG. 7.

[0046] In step S31 of FIG. 7, the abnormality detection unit 34 determines whether or not the condition that the amount of decrease in the current value flowing through the first conductive path 21 is equal to or greater than the first threshold value and the current value flowing through the second conductive path 22 has not increased is satisfied within a predetermined time. "The current value flowing through the second conductive path 22 has not increased" means, for example, "the current value flowing through the second conductive path 22 remains at 0 A".

[0047] When the first power supply unit 11 and the load 14 are not open-faulted, as shown in FIG. 2, the current value flowing through the first conductive path 21 is maintained at 100 A, and the current value flowing through the second conductive path 22 is maintained at 0 A. In this case, the abnormality detection unit 34 determines No in step S31. When the abnormality detection unit 34 determines No in step S31, it returns to step S31. That is, the abnormality detection unit 34 repeats the process of step S31 until it determines Yes in step S31.

[0048] When the load 14 has an open fault, as shown in FIG. 4, the current value flowing through the first conductive path 21 decreases to 0 A, and the current value flowing through the second conductive path 22 is maintained at 0 A. As a result, the abnormality detection unit 34 determines Yes in step S31. Then, the abnormality detection unit 34 determines whether the start switch of the vehicle is in the on state in step S32. When the abnormality detection unit 34 determines that the start switch is in the off state, it returns to step S31. When the abnormality detection unit 34 determines that the start switch is in the on state, it determines in step S33 that the load 14 has an open fault.

[0049] In this way, the abnormality detection unit 34 can determine that the load 14 has an open fault when the decrease amount of the current value flowing through the first conductive path 21 is equal to or greater than the first threshold value and the current value flowing through the second conductive path 22 has not increased at a predetermined time. Also, by making it a condition that the start switch of the vehicle is maintained in the on state, it is possible to exclude the case where the load 14 stops normally when the start switch is switched to the off state.

[0050] Note that the abnormality detection unit 34 may omit the process of step S32 in FIG. 7 and perform the process of FIG. 7 only when the start switch is in the on state.

[0051] 1-6. Example 2 of Determining an Open Circuit Fault in Load 14 As another example, if the vehicle's start switch remains ON for a predetermined time, and the decrease in the current flowing through the first conductive path 21 exceeds a first threshold, and the decrease in the current flowing through the third conductive path 23 exceeds a fourth threshold, then it is determined that load 14 has an open circuit fault. The fourth threshold may be the same as or different from the first threshold.

[0052] The abnormality detection unit 34 performs the process shown in Figure 8. The abnormality detection unit 34 starts the process shown in Figure 8 when the start switch is turned ON. In step S41 of Figure 8, the abnormality detection unit 34 determines whether, within a predetermined time, the decrease in the current value flowing through the first conductive path 21 is equal to or greater than the first threshold, and the decrease in the current value flowing through the third conductive path 23 is equal to or greater than the fourth threshold.

[0053] If the first power supply unit 11 and the load 14 are not open faults, the current values ​​flowing through the first conductive path 21 and the third conductive path 23 are maintained at 100A, as shown in Figure 2. In this case, the abnormality detection unit 34 determines No in step S41. If the abnormality detection unit 34 determines No in step S41, it returns to step S41. In other words, the abnormality detection unit 34 repeats the process of step S41 until it determines Yes in step S41.

[0054] If load 14 experiences an open fault, the current flowing through the first conductive path 21 and the third conductive path 23 decreases to 0A, as shown in Figure 4. As a result, the abnormality detection unit 34 determines Yes in step S41. Then, in step S42, the abnormality detection unit 34 determines whether the vehicle's start switch is ON or OFF. If the abnormality detection unit 34 determines that the start switch is OFF, it returns to step S41. If the abnormality detection unit 34 determines that the start switch is ON, it determines in step S43 that load 14 has experienced an open fault.

[0055] Thus, the abnormality detection unit 34 can determine that the load 14 has an open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path 21 exceeds a first threshold, and the decrease in the current value flowing through the third conductive path 23 exceeds a fourth threshold. Furthermore, by requiring that the vehicle's start switch be kept in the ON state, it is possible to eliminate cases where the load stops normally due to the start switch being switched to the OFF state.

[0056] The abnormality detection unit 34 may omit the process in step S42 of Figure 8 and perform the process shown in Figure 8 only when the start switch is ON.

[0057] 2. Second Embodiment In the second embodiment, a configuration in which multiple loads are provided will be described. In the second embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations are omitted.

[0058] Figure 9 shows an in-vehicle system 201 including an abnormality detection device 230 according to the second embodiment. The in-vehicle system 201 comprises a first power supply unit 11, a second power supply unit 12, a power line 13, and loads 14A, 14B, and 14C.

[0059] Load 14A is electrically connected to connection point 15A of the power line 13. Load 14B is electrically connected to connection point 15B of the power line 13. Load 14C is electrically connected to connection point 15C of the power line 13. Each load 14A, 14B, and 14C operates when the vehicle's start switch is ON and stops when the start switch is OFF, just like load 14 in the first embodiment.

[0060] The first conductive path 21 is provided between the first power supply unit 11 and connection points 15A, 15B, and 15C. The second conductive path 22 is provided between the second power supply unit 12 and connection points 15A, 15B, and 15C. A fourth conductive path 24 is provided between the first conductive path 21 and the second conductive path 22. The third conductive paths 23A, 23B, and 23C are provided individually corresponding to each load 14A, 14B, and 14C. Each load 14A, 14B, and 14C is electrically connected to the fourth conductive path 24 via the third conductive path 23A, 23B, and 23C corresponding to it.

[0061] The abnormality detection device 230 includes a first current sensor 31, a second current sensor 32, third current sensors 33A, 33B, and 33C, and an abnormality detection unit 34. The third current sensor 33A detects the current flowing through the third conductive path 23A. The third current sensor 33B detects the current flowing through the third conductive path 23B. The third current sensor 33C detects the current flowing through the third conductive path 23C. Each of the third current sensors 33A, 33B, and 33C detects the current flowing from the power path 13 side to each load 14A, 14B, and 14C side. Signals indicating the detection results of the third current sensors 33A, 33B, and 33C are input to the abnormality detection unit 34.

[0062] The abnormality detection unit 34 performs the processing described in, for example, "1-3. Example 1 of Determination of Open Circuit Fault in the First Power Supply Unit 11" of the first embodiment. As a result, the abnormality detection unit 34 can detect an open circuit fault in the first power supply unit 11 even in a configuration in which multiple loads 14A, 14B, and 14C are connected to the fourth conductive path 24.

[0063] Furthermore, the abnormality detection unit 34 may perform the process shown in Figure 10 instead of the process shown in Figure 6 described in the first embodiment. The abnormality detection unit 34 may perform the process shown in Figure 10 only when the start switch is ON, or it may perform it regardless of whether the start switch is ON or OFF.

[0064] In step S51 of Figure 10, the abnormality detection unit 34 determines that the first power supply unit 11 is open fault if, within a predetermined time, the decrease in the current value flowing through the first conductive path 21 is equal to or greater than a first threshold, and the change in the total current value flowing through each of the third conductive paths 23A, 23B, and 23C is less than or equal to a fifth threshold. The fifth threshold is a value smaller than the value obtained by multiplying the number of loads 14A, 14B, and 14C (3 in this embodiment) by the first threshold. When the abnormality detection unit 34 determines whether or not the change in the total current value flowing through each of the third conductive paths 23A, 23B, and 23C is less than or equal to the fifth threshold, it may also determine whether or not the current value flowing through the third conductive paths 23A, 23B, and 23C has not changed. In this case, the abnormality detection unit 34 may determine that there has been no substantial change if the change in the total current value flowing through the third conductive paths 23A, 23B, and 23C is within 5%.

[0065] If the abnormality detection unit 34 determines No in step S51, it returns to step S51. In other words, the abnormality detection unit 34 repeats the process of step S51 until it determines Yes in step S51. If the abnormality detection unit 34 determines Yes in step S51, it determines in step S52 that the first power supply unit 11 has an open fault.

[0066] Thus, the abnormality detection unit 34 can determine that the first power supply unit 11 is experiencing an open fault if, within a predetermined time, the amount of decrease in the current value flowing through the first conductive path 21 is equal to or greater than a first threshold, and the amount of change in the total current value flowing through each of the third conductive paths 23A, 23B, and 23C is equal to or less than a fifth threshold.

[0067] <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.

[0068] In the first embodiment, a first current sensor 31, a second current sensor 32, and a third current sensor 33 were provided, but any configuration that provides at least two current sensors necessary for detecting abnormalities is acceptable.

[0069] In the second embodiment, a first current sensor 31, a second current sensor 32, and third current sensors 33A, 33B, and 33C were provided, but any configuration that provides at least two types of current sensors necessary for detecting abnormalities is acceptable.

[0070] 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.

[0071] 1...In-vehicle system 11...First power supply unit 12...Second power supply unit 13...Power line 14...Load 14A...Load 14B...Load 14C...Load 15...Connection point 15A...Connection point 15B...Connection point 15C...Connection point 21...First conductive line 22...Second conductive line 23...Third conductive line 23A...Third conductive line 23B...Third conductive line 23C...Third conductive line 24...Fourth conductive line 30...Anomaly detection device 31...First current sensor 32...Second current sensor 33...Third current sensor 33A...Third current sensor 33B...Third current sensor 33C...Third current sensor 34...Anomaly detection unit 201...In-vehicle system 230...Anomaly detection device

Claims

1. An anomaly detection device included in an in-vehicle system comprising a first power supply unit, a second power supply unit, a power path provided between the first power supply unit and the second power supply unit, and a load electrically connected to the connection point of the power path, the anomaly detection device comprising an anomaly detection unit for detecting an anomaly, wherein the output voltage of the first power supply unit is higher than the output voltage of the second power supply unit, and the anomaly detection unit detects an open fault in at least one of the first power supply unit and the load based on the amount of change in the current value flowing through at least two conductive paths, which are provided between the first power supply unit and the connection point, the second conductive path provided between the second power supply unit and the connection point, and the third conductive path provided between the load and the connection point.

2. The abnormality detection device according to claim 1, wherein the abnormality detection unit determines that the first power supply unit is open fault when, within a predetermined time, the amount of decrease in the current value flowing through the first conductive path becomes equal to or greater than a first threshold, and the amount of increase in the current value flowing through the second conductive path becomes equal to or greater than a second threshold.

3. The abnormality detection device according to claim 1, wherein the abnormality detection unit determines that the first power supply unit is open fault when, within a predetermined time, the decrease in the current value flowing through the first conductive path is equal to or greater than a first threshold, and the fluctuation in the current value flowing through the third conductive path is less than or equal to a third threshold which is smaller than the first threshold.

4. The abnormality detection device according to claim 1, wherein the abnormality detection unit determines that the load is an open fault when, while the vehicle's start switch remains ON, the decrease in the current value flowing through the first conductive path becomes greater than or equal to a first threshold value for a predetermined time, and the current value flowing through the second conductive path does not increase.

5. The abnormality detection device according to claim 1, wherein the abnormality detection unit determines that the load is an open fault when, while the vehicle's start switch remains ON, the decrease in the current value flowing through the first conductive path becomes greater than or equal to a first threshold, and the decrease in the current value flowing through the third conductive path becomes greater than or equal to a fourth threshold, within a predetermined time.

6. An anomaly detection device according to claim 2, wherein a fourth conductive path is provided between the first conductive path and the second conductive path, a plurality of loads are provided, the third conductive path is provided to correspond individually to each load, and each load is electrically connected to the fourth conductive path via the third conductive path corresponding to itself.

7. A fourth conductive path is provided between the first conductive path and the second conductive path; a plurality of loads are provided; the third conductive path is provided to correspond individually to each load; each load is electrically connected to the fourth conductive path via the third conductive path corresponding to itself; the abnormality detection unit determines that the first power supply unit is open fault when, within a predetermined time, the amount of decrease in the current value flowing through the first conductive path is equal to or greater than a first threshold, and the amount of change in the total current value flowing through each of the third conductive paths is equal to or less than a fifth threshold; and the fifth threshold is a value smaller than the value obtained by multiplying the number of loads by the first threshold, as described in claim 1.

Images