In-vehicle device, determination method, and computer program

Abstract

A vehicle-mounted device according to an embodiment of the present disclosure includes: an opening / closing device provided on a power line from a power supply device mounted on a vehicle; and a control section that controls power output to a downstream side in a flow direction of current from the power supply device by applying a voltage to the opening / closing device, acquires a current value corresponding to power output to the downstream side from the opening / closing device, and determines whether the opening / closing device is in a failure state based on a voltage application state to the opening / closing device, the acquired current value from the opening / closing device, and an input current value generated from power supplied from the power supply device.

Description

Technical Field

[0001] This technology relates to vehicle-mounted devices, determination methods, and computer programs. This application claims priority based on Japanese Application No. 2023-200166, filed on November 27, 2023, and invokes all the contents set forth in the aforementioned Japanese application. Background Technology

[0002] The vehicle is equipped with a power supply control device for controlling the supply of power from the battery to the load (see, for example, Patent Document 1). In the power supply control device described in Patent Document 1, a semiconductor switch is provided in the current path from the battery to the load, and the power supply from the battery to the load is controlled by switching the semiconductor switch to be on or off.

[0003] Semiconductor switches have a control terminal. For example, when the semiconductor switch is a FET (Field Effect Transistor), the control terminal is the gate. The resistance between the two ends of the semiconductor switch changes according to the voltage at the control terminal. By adjusting the voltage at the control terminal, the resistance between the two ends of the semiconductor switch is adjusted to a sufficiently small value, causing the semiconductor switch to turn on. By adjusting the voltage at the control terminal, the resistance between the two ends of the semiconductor switch is adjusted to a sufficiently large value, causing the semiconductor switch to turn off. Existing technical documents Patent documents

[0004] Patent document 1: Japanese Patent Application Publication No. 2013-143905. Summary of the Invention

[0005] An embodiment of the vehicle-mounted device disclosed herein includes: a switching device disposed on a power line from a power supply device mounted on a vehicle; and a control unit that controls the switching device to output power downstream in the direction of current flow from the power supply device by applying a voltage to the switching device. The control unit acquires a current value corresponding to the power output downstream from the switching device and determines whether the switching device is in a fault state based on the voltage applied to the switching device, the current value acquired from the switching device, and the input current value generated by the power supplied from the power supply device. Attached Figure Description

[0006] Figure 1 This is a block diagram showing the main structure of the power supply system. Figure 2 This is a block diagram illustrating an example of the structure of a microcomputer with a single ECU. Figure 3 This is a block diagram illustrating an example of the connection between a microcomputer (ECU) and an IPD. Figure 4 This is a flowchart illustrating the steps involved in fault diagnosis and processing. Figure 5 This is an explanatory diagram showing an example of a fault determination table. Figure 6 This is an explanatory diagram showing an example of a judgment result table. Detailed Implementation

[0007] [The problem this disclosure aims to solve] However, the viewpoint on effectively determining the fault status of the switching device in the power supply control device in Reference 1 was not considered.

[0008] This disclosure was made in view of the current situation, and its purpose is to provide a vehicle-mounted device, etc., that can effectively determine the fault status of the opening and closing device.

[0009] [The Effects of This Disclosure] In one embodiment of this disclosure, the vehicle-mounted device can effectively determine the fault state of the opening and closing device.

[0010] [Description of embodiments of this disclosure] First, embodiments of this disclosure are listed and described. At least some of the embodiments described below can be combined arbitrarily.

[0011] (1) The vehicle-mounted device disclosed herein includes: a switching device disposed on a power line from a power supply device mounted on a vehicle; and a control unit that controls the switching device to output power downstream in the direction of current flow from the power supply device by applying a voltage to the switching device, the control unit obtaining a current value corresponding to the power output downstream from the switching device, and determining whether the switching device is in a fault state based on the voltage applied to the switching device, the current value obtained from the switching device, and the input current value generated by the power supplied from the power supply device.

[0012] In this scheme, the switching device is, for example, an IPD (Intelligent Power Device), which, when a voltage is applied from the control unit, outputs power from the upstream power supply to the load connected to the downstream side. That is, the switching device functions as a switch that changes the power output to the load based on the voltage applied from the control unit. The switching device and the control unit are connected via two control lines. One control line is used by the control unit to apply voltage to the switching device. The other control line is used by the control unit to obtain the current value corresponding to the power output from the switching device to the downstream side. In other words, a microcomputer (microprocessor) with a control unit is connected to a switching device via two pin terminals. The switching device may sometimes malfunction, including: an open-circuit fault state where no power is output to the downstream side despite a high-level voltage being applied from the control unit; or a short-circuit fault state where power is output to the downstream side despite a low-level voltage (lower than the high-level voltage) being applied from the control unit. The control unit determines whether the switching device is faulty based on whether voltage is applied to the switching device and the current value obtained from the switching device. However, when the switching device is faulty, the current detection terminal, which detects the current value corresponding to the power output to the downstream side, may also be damaged. This can cause discrepancies between the current value obtained by the control unit from the switching device and the actual current value output to the downstream side. By determining whether the current value (input current value) of the power supplied to the vehicle-mounted device corresponds to the current value obtained from the switching device, the control unit can determine whether the switching device is faulty even if the current detection terminal is damaged. Therefore, the control unit does not need to obtain the voltage value of the power output to the downstream side of the switching device to determine faults, and the control line used to obtain the voltage value does not need to be connected to the pin terminals of the microcomputer equipped with the control unit. This reduces the number of pin terminals used in the microcomputer equipped with the control unit for connecting to a single switching device, allowing multiple switching devices to be connected to the control unit. In addition, the control unit can also obtain the voltage value converted from the current value sent from the switching device via the pull-down resistor, and determine whether the switching device is in a fault state based on the obtained voltage value.

[0013] (2) In the vehicle-mounted device of the present disclosure, the control unit obtains the input current value from an upstream device disposed on the upstream side of the power supply device, the switching device and the upstream switching device included in the upstream device are connected via the power line, and the input current value is the current value flowing through the power line.

[0014] In this solution, the control unit of the vehicle-mounted device obtains the input current value from an upstream device located upstream of the vehicle-mounted device. The vehicle-mounted device involved in this solution is, for example, a separate ECU (left-side ECU or right-side ECU), and the upstream device is, for example, a combined ECU (front-side ECU). The upstream device has a control unit, and the control unit of the upstream device can communicate with the control unit of the vehicle-mounted device, for example, via CAN or Ethernet. The control unit of the vehicle-mounted device can obtain the input power value from the control unit of the upstream device and, based on the input current value obtained from the control unit of the upstream device, determine whether the opening / closing device of the vehicle-mounted device is in a fault state.

[0015] (3) The vehicle-mounted device involved in one of the solutions disclosed herein has multiple opening and closing devices. When the input current value is inconsistent with the sum of the current values ​​obtained from each of the multiple opening and closing devices, the control unit determines that the opening and closing device is in a fault state.

[0016] In this scheme, the power supplied from the upstream device is distributed to multiple switching devices within the on-board unit, and output from each switching device to the downstream load. When a switching device is not in a fault state, the input current value is consistent with the sum of the current values ​​obtained by the control unit of the on-board unit from each switching device. When a switching device is in a fault state, the input current value may not be consistent with the sum of the current values ​​obtained by the control unit of the on-board unit from each switching device. The control unit of the on-board unit can determine whether a switching device is in a fault state by determining whether the input current value is consistent with the sum of the current values ​​obtained by the control unit of the on-board unit from each switching device.

[0017] (4) In the vehicle-mounted device involved in the present disclosure, when no voltage is applied to the switching device, when the current value obtained from the switching device is less than a predetermined threshold, the control unit determines whether the input current value is consistent with the sum of the current values ​​obtained from each of the multiple switching devices. If they are inconsistent, the control unit determines that the switching device is in a short-circuit fault state.

[0018] In this solution, the current detection terminal may sometimes be in a low-level stuck state: although the switching device is outputting power downstream, it continues to detect a current value lower than a predetermined threshold. When the control unit of the vehicle-mounted device does not apply voltage to the switching device, and the current value obtained by the control unit from the switching device is less than the predetermined threshold, two scenarios can be considered: the switching device is in a normal state, or the switching device is in a short-circuit fault state and the current detection terminal is in a low-level stuck state. In this case, the control unit of the vehicle-mounted device can determine whether the switching device is in a short-circuit fault state by determining whether the input current value is consistent with the sum of the current values ​​obtained from each switching device. Furthermore, the state where the control unit of the vehicle-mounted device does not apply voltage to the switching device includes the state where the control unit of the vehicle-mounted device applies a low-level voltage to the switching device.

[0019] (5) In the vehicle-mounted device involved in the present disclosure, when a voltage is applied to the switching device, when the current value obtained from the switching device is above a predetermined threshold, the control unit determines whether the input current value is consistent with the sum of the current values ​​obtained from each of the multiple switching devices. If they are inconsistent, the control unit determines that the switching device is in an open circuit fault state.

[0020] In this solution, the current detection terminal may sometimes be in a high-level stuck state: although the switching device is not outputting power to the downstream side, it still continuously detects a current value above a predetermined threshold. When the control unit of the vehicle-mounted device applies voltage to the switching device, if the current value obtained by the control unit from the switching device is above the predetermined threshold, two scenarios can be considered: the switching device is in a normal state, and the switching device is in an open-circuit fault state with the current detection terminal in a high-level stuck state. In this case, the control unit of the vehicle-mounted device can determine whether the switching device is in an open-circuit fault state by determining whether the current value of the power supplied to the vehicle-mounted device is consistent with the sum of the current values ​​obtained from each switching device. In addition, the state in which the control unit of the vehicle-mounted device applies voltage to the switching device includes the state in which the control unit of the vehicle-mounted device applies a high-level voltage to the switching device.

[0021] (6) The determination method involved in one of the solutions disclosed herein includes the following steps: obtaining a current value corresponding to the power output from the switching device to the downstream side, the switching device being provided on a power line from a power supply device, the power supply device being mounted on a vehicle; determining whether the switching device is in a fault state based on the voltage applied to the switching device, the current value obtained from the switching device, and the input current value generated by the power supplied from the power supply device.

[0022] In this solution, by determining whether the current value (input current value) of the power supplied to the vehicle-mounted device corresponds to the current value obtained from the switching device, it is possible to determine whether the switching device is in a faulty state even if the current value detection terminal of the switching device is damaged. Therefore, the control unit does not need to obtain the voltage value of the power output from the switching device to the downstream side in order to determine the fault of the switching device, and the control line used to detect the voltage value does not need to be connected to the pin terminals of the microcomputer equipped with the control unit. As a result, the number of pin terminals used in the microcomputer equipped with the control unit for connecting to a single switching device can be reduced, and many switching devices can be connected to the control unit.

[0023] (7) A computer program involved in one of the solutions disclosed herein causes a computer to perform the following processing: obtain a current value corresponding to the power output from the switching device to the downstream side, the switching device being provided on a power line from a power supply device mounted on a vehicle; and determine whether the switching device is in a fault state based on the voltage applied to the switching device, the current value obtained from the switching device, and the input current value generated by the power supplied from the power supply device.

[0024] In this solution, by determining whether the current value (input current value) of the power supplied to the vehicle-mounted device corresponds to the current value obtained from the switching device, it is possible to determine whether the switching device is in a faulty state even if the current value detection terminal of the switching device is damaged. Therefore, the control unit does not need to obtain the voltage value of the power output from the switching device to the downstream side in order to determine the fault of the switching device, and the control line used to detect the voltage value does not need to be connected to the pin terminals of the microcomputer equipped with the control unit. As a result, the number of pin terminals used in the microcomputer equipped with the control unit for connecting to a single switching device can be reduced, and many switching devices can be connected to the control unit.

[0025] [Details of the embodiments of this disclosure] Specific examples of the power supply control device according to embodiments of the present disclosure will be described below with reference to the accompanying drawings. Furthermore, the present disclosure is not limited to these examples, as indicated by the claims, and is intended to include all modifications within the same meaning and scope as the claims.

[0026] (Implementation Method) Figure 1 This is a block diagram showing the main structure of the power supply system S. Figure 1In the diagram, power lines are represented by solid lines, and control lines by dashed lines. Communication lines are represented by thick lines. The power supply system S is installed in vehicle M and includes a power supply unit 1, an integrated ECU (Electronic Control Unit) 2, individual ECUs 3, and multiple loads 4. The power supply unit 1 outputs direct current. The integrated ECU 2 acts as an upstream device, connected to the positive terminal of the power supply unit 1 and the individual ECU 3. The individual ECU 3 acts as an on-board device, connected to one end of the integrated ECU 2 and the multiple loads 4. The negative terminal of the power supply unit 1 and the other end of the loads 4 are grounded. Alternatively, the integrated ECU 2 can be a front-area ECU located in the front region of vehicle M, and the individual ECU 3 can be a left-side ECU located in the left-side region of vehicle M or a right-side ECU located in the right-side region. In the following description, in the current path from the power supply unit 1 to the loads 4, the power supply unit 1 side is designated as upstream, and the loads 4 side as downstream.

[0027] The integrated ECU2 includes a microcomputer (microcomputer) 21 and an IPD (Intelligent Power Device) 22. Power supplied from the power supply unit 1 is output downstream via the IPD 22 of the integrated ECU2. The IPD 22 acts as an upstream switching device. The microcomputer 21 controls the downstream power output of the IPD 22 and obtains the current value of the power output downstream by the IPD 22. The power output downstream via the IPD 22 is then supplied to the individual ECU3.

[0028] Each individual ECU 3 has a microcomputer 31 and multiple IPDs 32. Power supplied from the power supply unit 1 to the individual ECU 3 via IPDs 22 of the integrated ECU 2 is distributed to the multiple IPDs 32 and output to the downstream load 4 through each IPD 32. Each IPD 32 acts as a switching device. The microcomputer 31 controls the power output of the IPDs 32 to the downstream side and obtains the current value corresponding to the power output by the IPDs 32 to the downstream side.

[0029] The microcomputer 21 of the integrated ECU2 and the microcomputer 31 of the individual ECU3 are connected via communication bus B, enabling communication using protocols such as CAN (Control Area Network), CAN-FD, or Ethernet. The microcomputer 21 of the integrated ECU2 sends the current value of the power output from IPD22 to the downstream side, i.e., the current value (input current value) of the power supplied to the individual ECU3, to the microcomputer 31 of the individual ECU3. Alternatively, IPD22 (upstream switching device) and IPD32 (switching device) can also be housed within a single ECU. In this case, IPD22 (upstream switching device) and IPD32 (switching device) can also be controlled by the same microcomputer. Furthermore, the microcomputer 31 of the individual ECU3 can also control the power output of IPD22 from the integrated ECU2 to the downstream side and obtain the current value of the power output from IPD22 to the downstream side.

[0030] Figure 2 This is a block diagram illustrating an example of the structure of a microcomputer 31 with a separate ECU 3. The microcomputer 31 includes a control unit 311, a storage unit 312, an input / output (I / F) unit 313, and an in-vehicle communication unit 314. They are connected to an internal bus 315.

[0031] The control unit 311 has a processing element, such as a CPU (Central Processing Unit), that performs processing and functions as a processing unit. The processing element of the control unit 311 reads and executes the computer program P stored in the storage unit 312, thereby performing processes such as controlling the output of power from each IPD 32 to the downstream side, determining faults in each IPD 32, and recording the fault determination results of each IPD 32. Furthermore, the processing performed by the control unit 311 can also be performed by an external device connected to the individual ECU 3 wirelessly or via a wired connection.

[0032] Storage unit 312 is a non-volatile memory. Storage unit 312 stores a computer program P, a fault determination table T1, and a determination result table T2. Details of fault determination table T1 and determination result table T2 will be described later. The computer program P can also be provided to the microcomputer 31 using a non-temporary storage medium A on which the computer program P is readable. Storage medium A is, for example, a portable memory. When storage medium A is a portable memory, the processing element of control unit 311 can also read the computer program P from storage medium A using a reading device (not shown). The read computer program P is stored in storage unit 312. Furthermore, the computer program P can also communicate with an external device via a communication unit (not shown) of microcomputer 31, thereby providing it to microcomputer 31. In addition, storage unit 312 stores thresholds and coefficients, etc., as described later. Furthermore, the thresholds and coefficients stored in storage unit 312 can be changed, for example, by reprogramming, depending on the type of load 4 connected to individual ECU 3 or the type of IPD 32 equipped on individual ECU 3. Furthermore, the thresholds and coefficients stored in the storage unit 312 can also be updated through communication with external devices.

[0033] The input / output I / F313 is connected to multiple IPD32s via control lines. According to the instructions of the control unit 311, the input / output I / F313 switches the applied voltage to the IPD32 to a high-level voltage or a low-level voltage. Additionally, the voltage value corresponding to the current value output by the IPD32 is input to the input / output I / F313. The control unit 311 obtains the voltage values ​​input to the input / output I / F313.

[0034] The in-vehicle communication unit 314 uses an input / output interface that employs communication protocols such as CAN, CAN-FD, or Ethernet (registered trademark). The control unit 311 communicates with the integrated ECU 2 or other vehicle-mounted equipment via the in-vehicle communication unit 314. The in-vehicle communication unit 314 obtains the current value (input current value) of the power output from the integrated ECU 2's IPD 22 to the downstream side, i.e., the power supplied to the individual ECU 3, from the integrated ECU 2's microcomputer 21.

[0035] Figure 3 This is a block diagram showing an example of the connection between the microcomputer 31 of the separate ECU3 and the IPD32. Figure 3 The diagram shows a connection example of a microcomputer 31 to one IPD32, and descriptions of other IPD32s are omitted. The input / output I / F313 of the microcomputer 31 has multiple pin terminals (PIN(1), PIN(2)...PIN(n)).

[0036] IPD32 includes a power receiving terminal 321, a power output terminal 322, a voltage application terminal 323, and a current value detection terminal 324. The power line connecting IPD22 of the integrated ECU2 and IPD32 of the individual ECU3 is connected to the power receiving terminal 321, and the power receiving terminal 321 receives power supplied from the upstream side.

[0037] Connect the power line connecting IPD32 and load 4 to power output terminal 322. Power output terminal 322 outputs the power received by power receiving terminal 321 to the downstream load 4.

[0038] The voltage application terminal 323 is connected to the input / output (I / F) 313 of the microcomputer 31 via a control line. In this embodiment, the voltage application terminal 323 is connected to PIN (1) of the input / output (I / F) 313. The power output from the power output terminal 322 is controlled based on the voltage application state of the voltage application terminal 323 controlled by the microcomputer 31. Specifically, the IPD 32 may include, for example, an N-channel FET (Field Effect Transistor). The drain of the FET is connected to the power receiving terminal 321, and the source is connected to the power output terminal 322. The gate of the FET is connected to the voltage application terminal 323, and the voltage applied to the voltage application terminal 323 is applied to the gate of the FET. Thus, when a high-level voltage is applied to the voltage application terminal 323, the power received by the power receiving terminal 321 (the power supplied to the IPD 32) is output to the downstream load 4 via the FET from the power output terminal 322. When a low-level voltage is applied to the voltage application terminal 323, no power is output from the power output terminal 322 to the downstream load 4. Alternatively, the switching device (IPD32) can also be composed of a P-channel FET or a mechanical relay.

[0039] The current detection terminal 324 is connected to the input / output (I / F) 313 of the microcomputer 31 via a control line. In this embodiment, the current detection terminal 324 is connected to PIN (2) of the input / output (I / F) 313. The current detection terminal 324 outputs a current value to the microcomputer 31 corresponding to the power output from the power output terminal 322. Specifically, the IPD 32 includes, for example, a current detection circuit. The current detection circuit is connected between the source of the FET and the power output terminal 322. Furthermore, the current detection terminal 324 is connected to the current detection circuit and outputs a current value to the microcomputer 31, which is the current value of the power output from the power output terminal 322 detected by the current detection circuit multiplied by a predetermined coefficient. In addition, a pull-down resistor R is connected between the power output terminal 322 and the microcomputer 31. Thus, the microcomputer 31 can obtain a voltage value proportional to the current value output by the current detection terminal 324. That is, the microcomputer 31 can obtain a voltage value that is proportional to the current value (output current value) of the power output terminal 322 of the IPD 32.

[0040] The other IPDs 32 in the individual ECU 3 also have, as described above, a power receiving terminal 321, a power output terminal 322, a voltage application terminal 323, and a current value detection terminal 324. In addition, one IPD 32 is connected to two pin terminals in the microcomputer 31.

[0041] Figure 4 This is a flowchart illustrating the steps of the fault diagnosis process. The control unit 311 of the individual ECU3 obtains the voltage application state of the IPD32 (S1). The control unit 311 obtains the current value (output current value) of the power output from the power output terminal 322 of the IPD32 that is the target of fault diagnosis (S2). Furthermore, the control unit 311 obtains the output current value of other IPD32s that are not the target of fault diagnosis (S3). Additionally, in S2 and S3, the control unit 311 performs calculations based on the voltage value obtained at the pin terminal connected to the current value detection terminal of the IPD32, thereby obtaining the output current value of the IPD32. The control unit 311 obtains the input current value to the individual ECU3 from the microcomputer 21 of the integrated ECU2 (S4).

[0042] The control unit 311 of the microcomputer 31 determines whether the voltage applied to the IPD 32, which is the target of fault determination, is a high-level voltage (S5). When the voltage applied to the IPD 32 is a high-level voltage (S5: Yes), the control unit 311 determines whether the output current value of the IPD 32, which is the target of fault determination, is above a predetermined threshold (S6). The threshold in S6 is the current value of the minimum current value among the cutoff characteristics of the load to which the IPD 32 is supposed to be connected. In addition, the control unit 311 can also determine whether the IPD 32 has output current, that is, whether the output current value is higher than 0A or 0A. When the output current value of the IPD 32, which is the target of fault determination, is above the predetermined threshold (S6: Yes), the control unit 311 determines whether the input current value to the IPD 32 is consistent with the sum of the output current values ​​of all the IPD 32s possessed by the individual ECU 3 (S7). When the sum of the input current value and the output current value is consistent (S7: Yes), the control unit 311 determines that the IPD 32, which is the target of fault determination, is in a normal state (S8). When the output current value of the IPD32, which is the target of fault determination, is not above a predetermined threshold (i.e., less than the threshold) (S6: No), or when the sum of the input current value and the output current value is inconsistent (S7: No), the control unit 311 determines that the IPD32, which is the target of fault determination, is in an open-circuit fault state (S9). In addition, when it is determined that the IPD32 is in an open-circuit fault state, the control unit 311 may, for example, stop controlling the IPD32 that is determined to be in an open-circuit fault state.

[0043] When the voltage applied to IPD32 is not a high-level voltage (it is a low-level voltage) (S5: No), the control unit 311 determines whether the output current value of IPD32, which is the target of fault determination, is above a predetermined threshold (S10). The threshold in S10 is the current value of the minimum current value among the cutoff characteristics of the load to which the IPD32 is supposed to be connected. In addition, the control unit 311 can also determine whether IPD32 has output current, that is, whether the output current value is higher than 0A or 0A. When the output current value of IPD32, which is the target of fault determination, is not above the predetermined threshold (i.e., less than the threshold) (S10: No), the control unit 311 determines whether the input current value to IPD32 is consistent with the sum of the output current values ​​of all IPD32s possessed by the individual ECU3 (S11). When the sum of the input current value and the output current value is consistent (S11: Yes), the control unit 311 determines that IPD32, which is the target of fault determination, is in a normal state (S12). When the output current of IPD32, the object of fault determination, exceeds a predetermined threshold (S10: Yes), or when the sum of the input current and the output current is inconsistent (S11: No), the control unit 311 determines that IPD32, the object of fault determination, is in a short-circuit fault state (S13). Furthermore, when it is determined that IPD32 is in a short-circuit fault state, the control unit 311 may, for example, send a signal to the microcomputer 21 of the integrated ECU2 requesting to stop supplying power to the individual ECU3.

[0044] After determining the state of IPD32 in S8, S9, S12 or S13, the control unit 311 stores (saves) the determination result in the determination result table (S14) and ends the process.

[0045] Figure 5 This is an explanatory diagram showing an example of the fault determination table T1. The control unit 311 of the individual ECU3 can also determine the status of IPD32 by referring to the fault determination table T1. The management items (fields) of the fault determination table T1 include, for example, the following: condition fields, including voltage application field, output current value field and input current value field; and status fields, including IPD status field and current value detection terminal status field.

[0046] Each field in the Conditions field stores the conditions used to determine the state of IPD32. The Voltage Application field stores the voltage application state of IPD32 from the microcomputer 31. When a low-level voltage is applied to IPD32, the Voltage Application field stores "L". When a high-level voltage is applied to IPD32, the Voltage Application field stores "H".

[0047] The output current value field stores the threshold conditions for the output current value of IPD32 obtained by the control unit 311. When the output current value is less than the threshold, the output current value field stores "L". When the output current value is greater than the threshold, the output current value field stores "H".

[0048] The input current value field stores the condition of whether the input current value obtained by the control unit 311 from the microcomputer 21 of the integrated ECU2 is consistent with the sum of the output current values ​​of all IPDs 32 of the individual ECU3. When the condition indicates that the sum of the input current value and the output current value are consistent, the input current value field stores "consistent". When the condition indicates that the sum of the input current value and the output current value are inconsistent, the input current value field stores "inconsistent". Furthermore, when the consistency between the input current value and the output current value is not considered, the input current value field stores a blank value.

[0049] In each field of the status field, the status of the IPD32 or the current value detection terminal determined by the control unit 311 is stored relative to the conditions stored in the condition field. The IPD status field stores the status of the IPD32 determined by the control unit 311 relative to the conditions. The current value detection terminal status field stores the status of the current value detection terminal of the IPD32 determined by the control unit 311 relative to the conditions.

[0050] When a low-level voltage is applied to IPD32, if the output current value is less than the threshold and the sum of the input and output current values ​​is the same, IPD32 and the current detection terminal 324 are determined to be in a normal state. When a low-level voltage is applied to IPD32, if the output current value is greater than the threshold, IPD32 is determined to be in a short-circuit fault state, and the current detection terminal 324 is determined to be in a normal state or a high-level stuck state. When a low-level voltage is applied to IPD32, if the output current value is less than the threshold and the sum of the input and output current values ​​is not the same, IPD32 is determined to be in a short-circuit fault state, and the current detection terminal 324 is determined to be in a low-level stuck state.

[0051] When a high-level voltage is applied to IPD32, if the output current value is above the threshold and the sum of the input and output current values ​​is the same, IPD32 and the current detection terminal 324 are determined to be in a normal state. When a high-level voltage is applied to IPD32, if the output current value is less than the threshold, IPD32 is determined to be in an open-circuit fault state, and the current detection terminal 324 is determined to be in a normal state or a low-level stuck state. When a high-level voltage is applied to IPD32, if the output current value is above the threshold and the sum of the input and output current values ​​is not the same, IPD32 is determined to be in an open-circuit fault state, and the current detection terminal 324 is determined to be in a high-level stuck state.

[0052] Figure 6 This is an explanatory diagram showing an example of a judgment result table T2. In the judgment result table T2, the time when the control unit 311 made a judgment, information about the IPD 32 whose state was determined, and the judgment result are stored together. Management items in the judgment result table include, for example, a judgment time field, a judgment IPD field, and a judgment result field.

[0053] The determination time field stores, for example, the time when the control unit 311 of the microcomputer 31 determines the state of the IPD 32, based on the time when the vehicle M starts and the microcomputer 31 begins controlling each IPD 32 (time 0). The control unit 311 determines the state of the multiple IPD 32s of each individual ECU 3 sequentially, for example, at a period of 5 milliseconds. In addition, the period for the control unit 311 to make the determination is not limited to 5 milliseconds, but may also be 10 milliseconds, for example.

[0054] The determination IPD field stores information used to identify the IPD32 whose state has been determined (becoming the object of fault determination). In this embodiment, each of the multiple IPD32s possessed by a single ECU3 is assigned a symbol (IPD32(a), IPD32(b), IPD32(c)...) to identify each IPD32. The determination IPD field stores the symbol of the IPD32 whose state has been determined. Furthermore, after determining the state of all IPD32s, the control unit 311 starts again from IPD32(a) and repeatedly determines the state of all IPD32s in sequence. The control unit 311 outputs the determination result of each IPD32 in sequence at a predetermined period, and saves the output determination result in a new record of the determination result table T2 each time.

[0055] The determination result field stores the determination result of the control unit 311 on the status of IPD32 (any one of "normal", "short circuit fault" or "open circuit fault"). In addition, the determination result table T2 may also have a current value detection terminal status determination result field, and store the status of the current value detection terminal 324 of IPD32 determined by the control unit 311.

[0056] It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The technical features described in the various embodiments can be combined with each other, and the scope of the invention is intended to include all variations within the claims and the scope equivalent to the claims. Furthermore, the independent and dependent claims described in the claims can be combined with each other in all combinations, regardless of the form of reference. Moreover, the claims are written in a format that references two or more claims (multiple reference claim format), but are not limited to this. A format that references at least one multiple claim (multiple references to multiple claims) may also be used. Symbol Explanation

[0057] 1. Power supply unit 2 Integrated ECU 21 Microcomputer 22 IPD 3. Separate ECU 31 Microcomputer 311 Control Department 312 Storage Department 313 Input / Output I / F 314 In-vehicle Communication Department 32 IPD 321 Power receiving terminal 322 Power Output Terminal 323 Voltage application terminal 324 Current value detection terminal 4. Load A storage medium M vehicle P Computer Program S power supply system T1 Fault Judgment Table T2 Judgment Result Table.

Claims

1. A vehicle-mounted device, comprising: An opening and closing device is provided on a power line from a power source mounted on a vehicle; and The control unit controls the downstream power output of the switching device in the direction of current flow from the power supply device by applying a voltage to the switching device. The control unit acquires a current value corresponding to the power output from the switching device to the downstream side, and determines whether the switching device is in a fault state based on the voltage applied to the switching device, the current value acquired from the switching device, and the input current value generated by the power supplied from the power supply device.

2. The vehicle-mounted device according to claim 1, wherein, The control unit obtains the input current value from an upstream device located on the upstream side of the power supply device. The switching device is connected to the upstream switching device included in the upstream device via the power line. The input current value is the current value flowing through the power line.

3. The vehicle-mounted device according to claim 1 or 2, wherein, The vehicle-mounted device includes multiple opening and closing devices. If the input current value is inconsistent with the sum of the current values ​​obtained from each of the multiple switching devices, the control unit determines that the switching device is in a faulty state.

4. The vehicle-mounted device according to claim 3, wherein, When no voltage is applied to the switching device, and the current value obtained from the switching device is less than a predetermined threshold, the control unit determines whether the input current value is consistent with the sum of the current values ​​obtained from each of the multiple switching devices. When there is a discrepancy, the control unit determines that the opening and closing device is in a short-circuit fault state.

5. The vehicle-mounted device according to claim 3, wherein, When a voltage is applied to the switching device, if the current value obtained from the switching device is above a predetermined threshold, the control unit determines whether the input current value is consistent with the sum of the current values ​​obtained from each of the plurality of switching devices. When there is a discrepancy, the control unit determines that the opening and closing device is in an open circuit fault state.

6. A determination method, comprising the following steps: Obtain the current value corresponding to the power output from the switching device to the downstream side, the switching device being located on the power line from the power supply device, the power supply device being mounted on the vehicle; The fault status of the switching device is determined based on the voltage applied to the switching device, the current value obtained from the switching device, and the input current value generated by the power supplied from the power supply device.

7. A computer program that causes a computer to perform the following processes: Obtain the current value corresponding to the power output from the switching device to the downstream side, the switching device being located on the power line from the power supply device, the power supply device being mounted on the vehicle; The fault status of the switching device is determined based on the voltage applied to the switching device, the current value obtained from the switching device, and the input current value generated by the power supplied from the power supply device.

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