Vehicle control device

Abstract

The vehicle-mounted control device (10) is included in an in-vehicle system (100) including a power path (80) that supplies power from a power source unit (90) to a load (91), a relay (11) provided on the power path (80), and a cutoff unit (12) provided on the power path (80). The vehicle-mounted control device (10) includes a control unit (14) that controls the cutoff unit (12). The cutoff unit (12) switches from a permissive state that allows power to be supplied from the power source unit (90) side to the load (91) side to a cutoff state that cuts off the power. When the current value flowing through the relay (11) exceeds a threshold value, the control unit (14) switches the cutoff unit (12) to the cutoff state based on the elapsed time since the current value exceeded the threshold value and the current value after the current value exceeded the threshold value.

Description

[Technical field]

[0001] The present disclosure relates to an in-vehicle control device. [Background technology]

[0002] The background art of Patent Document 1 discloses a load circuit that supplies power to a load. This load circuit includes a battery and a relay (semiconductor switch) provided between the battery and the load, and the load is driven and stopped by turning the relay on and off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-35951 A Summary of the Invention [Problem to be solved by the invention]

[0004] If an overcurrent continues to flow through a relay, it may cause an abnormality such as the relay emitting smoke. Therefore, it is conceivable to prevent the occurrence of the above abnormality by providing a cutoff unit separate from the relay, which cuts off the power path when a current exceeding a threshold continues to flow for a certain period of time. However, the time until the above abnormality occurs varies depending on the current value after exceeding the threshold. For this reason, it is desirable to cut off the power path taking into account the time that has elapsed since the current value flowing through the relay exceeded the threshold and the current value after exceeding the threshold.

[0005] The present disclosure aims to provide a technology that can switch a breaker to a break state by taking into account the time that has elapsed since the current value flowing through a relay exceeded a threshold and the current value after exceeding the threshold. [Means for solving the problem]

[0006] The in-vehicle control device of the present disclosure includes: An in-vehicle control device included in an in-vehicle system including a power path for supplying power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, When a current value flowing through the relay exceeds a threshold, the control unit switches the interrupter to the interrupt state based on the time elapsed since the current value exceeded the threshold and the current value after the current value exceeded the threshold. Effect of the Invention

[0007] The technology disclosed herein can switch the interrupter to the interrupt state by taking into consideration the time that has elapsed since the value of the current flowing through the relay exceeded a threshold and the value of the current after exceeding the threshold. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an in-vehicle system including an in-vehicle control device according to the first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing graphs G1 and G2. [Diagram 3] FIG. 3 is an explanatory diagram showing the corresponding data DA. [Figure 4] FIG. 4 is an explanatory diagram showing the correspondence data DB. [Diagram 5] FIG. 5 is an explanatory diagram showing the correspondence data DC. [Figure 6] FIG. 6 is an explanatory diagram showing the TC corresponding data DD. [Figure 7] FIG. 7 is a flowchart showing the flow of the process performed by the control unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiments of the present disclosure] Below, embodiments according to the present disclosure are listed and illustrated.

[0010] [1] An in-vehicle control device included in an in-vehicle system including a power path that supplies power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, When a value of a current flowing through the relay exceeds a threshold, the control unit switches the interrupting unit to the interrupting state based on an elapsed time since the current value exceeded the threshold and the current value after the current value exceeded the threshold. In-vehicle control device.

[0011] The vehicle control device switches the breaker to the break state based on the time that has elapsed since the current value flowing through the relay exceeded the threshold and the current value after the threshold was exceeded, that is, the vehicle control device can switch the breaker to the break state taking into account the time that has elapsed since the current value flowing through the relay exceeded the threshold and the current value after the threshold was exceeded.

[0012] [2] The threshold value is less than the maximum rated current of the vehicle. The vehicle-mounted control device described in [1].

[0013] The vehicle-mounted control device can switch the cutoff unit to the cutoff state when the value of the current flowing through the relay exceeds a threshold value that is set to a value smaller than the maximum rated current of the vehicle.

[0014] [3] The threshold value is a value smaller than a maximum interruptable current, which is a maximum current at which the relay can be switched from an on state to an off state. The vehicle-mounted control device described in [1].

[0015] The vehicle-mounted control device can switch the interrupter to the interrupt state when the value of the current flowing through the relay exceeds a threshold value that is set to a value smaller than the maximum interruptable current.

[0016] [4] When the current value exceeds the threshold, the control unit determines whether or not a time integral of the current value after exceeding the threshold exceeds a corresponding value corresponding to the elapsed time, and switches the cutoff unit to the cutoff state when it is determined that the time integral has exceeded the corresponding value. An in-vehicle control device according to any one of [1] to [3].

[0017] The vehicle-mounted control device can switch the cutoff unit to the cutoff state when the time integral value of the current value accumulates to a value exceeding a corresponding value corresponding to the elapsed time.

[0018] [5] When the current value exceeds the threshold, the control unit determines whether or not a time integral of the square of the current value after the current value exceeds the threshold exceeds a corresponding value corresponding to the elapsed time, and switches the cutoff unit to the cutoff state when it is determined that the corresponding value has been exceeded. An in-vehicle control device according to any one of [1] to [3].

[0019] The vehicle-mounted control device can switch the cutoff unit to the cutoff state when a time integral value of the square of the current value accumulates to a value exceeding a corresponding value corresponding to an elapsed time.

[0020] [6] A cutoff upper limit value is set in advance, the upper limit value being greater than the threshold value and less than a maximum current that can be passed, which is a maximum current that allows the relay to maintain an on-state; When the current value exceeds the upper cut-off limit, the control unit switches the cut-off unit to the cut-off state regardless of the elapsed time. An in-vehicle control device according to any one of [1] to [5].

[0021] The above-mentioned vehicle control device switches the cut-off unit to the cut-off state regardless of the elapsed time when the current value flowing through the relay exceeds the upper cut-off limit value, making it easy to switch the cut-off unit to the cut-off state before the relay starts to smoke or catch fire.

[0022] [7] The maximum current that can be passed is smaller than a saturation current that flows through the power path when the power path has a ground fault, The cut-off upper limit value is set in consideration of a time lag from when it is determined that the current value has exceeded the cut-off upper limit value until the cut-off unit switches to the cut-off state, so that the cut-off unit switches to the cut-off state before the current value reaches the saturation current. The vehicle-mounted control device described in [6].

[0023] The vehicle-mounted control device can switch the interrupter to the interrupt state before the value of the current flowing through the relay reaches the saturation current.

[0024] [8] The upper limit of the interruption is set in consideration of a time lag between when it is determined that the current value has exceeded the upper limit of the interruption and when the interrupter is switched to the interruption state, so that the interrupter is switched to the interruption state before the current value reaches the maximum current that can be passed. The vehicle-mounted control device described in [6].

[0025] The vehicle control device can switch the breaker to the break state before the current value flowing through the relay reaches the maximum current that can be passed, thereby preventing the relay from being unable to maintain the on state due to a current that exceeds the maximum current that can be passed through the relay.

[0026] [9] The relay is controlled by a second control unit different from the control unit; When the control unit determines that the second control unit has controlled the relay to an off state while the current value exceeds the threshold value, the control unit switches the interrupter to the interruption state regardless of the elapsed time. An in-vehicle control device according to any one of [1] to [8].

[0027] It is also assumed that even if the second control unit attempts to switch the relay to the off state, the relay may not switch to the off state due to a failure of the relay, etc. Even if such a situation occurs, the above-mentioned on-board control device can more reliably interrupt the current flowing through the power path by switching the interrupter to the interruption state when the second control unit attempts to switch the relay to the off state.

[0028] [Details of the embodiment of the present disclosure] First Embodiment 1 shows an in-vehicle system 100 including an in-vehicle control device 10. The in-vehicle system 100 is a system mounted on a vehicle. The in-vehicle system 100 includes a power supply unit 90, a load 91, and a power path 80.

[0029] The power supply unit 90 is, for example, a DC power supply that generates a DC voltage, such as a battery. The battery is, for example, a lead battery, a lithium ion battery, or the like. The load 91 is an electronic component provided in the vehicle. The load 91 is, for example, an electric component, an ECU, an ADAS target component, or the like. The power path 80 is provided between the power supply unit 90 and the load 91. The power path 80 supplies power from the power supply unit 90 to the load 91. One end of the power path 80 is electrically connected to the power supply unit 90, and the other end is electrically connected to the load 91.

[0030] The vehicle-mounted control device 10 includes a relay 11, a breaker unit 12, a current detector 13, a controller 14, and a second controller 15.

[0031] The relay 11 is provided on the power path 80. When the relay 11 is in an on state, a current is conducted between the power path 80 and the load 91. When the relay 11 is in an off state, a current is not conducted between the power path 80 and the load 91. The relay 11 is controlled by a second control unit 15. In this embodiment, the relay 11 is configured as an electromagnetic relay, and has contacts that are operated by electromagnetic force.

[0032] The interrupter 12 is provided on the power path 80. The interrupter 12 switches from an allowable state, which allows power to be supplied from the power supply unit 90 to the load 91, to a cutoff state, which cuts off the power. The interrupter 12 may be configured to be able to return to an allowable state after being in the cutoff state, or may be configured not to be able to return to the allowable state. The interrupter 12 is configured, for example, as a pyrotechnic circuit breaker, a semiconductor switch, an electromagnetic fuse, or the like. The pyrotechnic circuit breaker is a circuit breaker that physically cuts off the power path 80 in response to input of a drive signal, and is, for example, a pyrotechnic fuse (PYROFUSE (registered trademark). The interrupter 12 is controlled by the control unit 14.

[0033] The current detection unit 13 is configured as, for example, a known current sensor. The current detection unit 13 detects the current flowing through the relay 11. The current detection unit 13 outputs a signal that can identify the detected value. This signal is input to the control unit 14 and the second control unit 15, respectively.

[0034] The control unit 14 controls the breaker unit 12. The control unit 14 is configured as, for example, an MCU (Micro Controller Unit). The control unit 14 is configured as a device separate from the second control unit 15. The control unit 14 detects the value of the current flowing through the relay 11 based on the signal output from the current detection unit 13.

[0035] When the current value flowing through relay 11 exceeds threshold A, control unit 14 switches cutoff unit 12 to the cutoff state based on the time EA that has elapsed since the current value exceeded threshold A and the current value after the current value exceeded threshold A. Threshold A is a value smaller than the maximum rated current IA of the vehicle. For example, a battery management system that manages power supply unit 90 (specifically, a battery) treats a current that exceeds the maximum rated current IA as an overflow. For example, the battery management system treats a current that exceeds the maximum rated current IA as the maximum rated current IA when calculating SOC (State Of Charge). For example, the current consumption of load 91 is limited so as not to exceed the maximum rated current IA.

[0036] When the current value flowing through the relay 11 exceeds the threshold A, the control unit 14 judges whether or not the time integral value ZA of the current value after exceeding the threshold A exceeds the corresponding value CA corresponding to the elapsed time EA, and switches the breaker unit 12 to the breaker state when it is judged that the time integral value ZA has exceeded the corresponding value CA. The control unit 14 prestores the corresponding data DA indicating the correspondence relationship between the elapsed time EA and the corresponding value CA. The corresponding data DA may be a function indicating the correspondence relationship between the elapsed time EA and the corresponding value CA, or may be table data indicating the correspondence relationship between the elapsed time EA and the corresponding value CA. The corresponding data DA is set to have the breaker characteristics shown by the graph G1 in FIG. 2. The graph G1 indicates the time until the breaker is broken when the current of the current value continues to flow for each current value in a predetermined current value range. The graph G1 indicates the characteristic that the breaker is broken in a shorter time as the current value increases.

[0037] When the current value flowing through the relay 11 exceeds the threshold A, the control unit 14 repeatedly calculates the time integral value ZA of the current value after exceeding the threshold A. For example, as shown in FIG. 3, the control unit 14 first calculates ZA1 as the time integral value ZA. In the next period, the control unit 14 adds ZA2 to the time integral value ZA calculated in the previous period to obtain a new time integral value ZA. The control unit 14 repeatedly calculates the time integral value ZA by repeating such processing. The control unit 14 uses the corresponding data DA to derive a corresponding value CA corresponding to the elapsed time EA. The control unit 14 repeatedly determines whether the time integral value ZA exceeds the corresponding value CA. In the example shown in FIG. 3, the time integral value ZA in the sixth period to which ZA6 is added exceeds the corresponding value CA. When the control unit 14 determines that the time integral value ZA exceeds the corresponding value CA, the control unit 14 switches the cutoff unit 12 to the cutoff state.

[0038] The time integral value ZA may be reset to 0 when a first reset condition is satisfied. The first reset condition may be that a certain time has elapsed since the value of the current flowing through relay 11 exceeded threshold value A, or that the value of the current flowing through relay 11 has fallen below threshold value A, or may be another condition.

[0039] When the value of the current flowing through the relay 11 exceeds threshold B, the control unit 14 switches the interrupting unit 12 to the interrupted state based on the time that has elapsed since the current value exceeded threshold B and the current value after the current value exceeded threshold B. Threshold B is a value smaller than the maximum interruptible current IB. In this embodiment, threshold B is the same as threshold A, but it may be larger or smaller than threshold A. The maximum interruptible current IB is the maximum current at which the relay 11 can be switched from an on state to an off state.

[0040] When the current value flowing through the relay 11 exceeds the threshold B, the control unit 14 determines whether or not a time integral value ZB of the current value after exceeding the threshold B exceeds a corresponding value CB corresponding to the elapsed time EB, and switches the breaker unit 12 to the breaker state when it is determined that the current value has exceeded the corresponding value CB. The control unit 14 prestores a correspondence data DB indicating the correspondence relationship between the elapsed time EB and the corresponding value CB. The correspondence data DB may be a function indicating the correspondence relationship between the elapsed time EB and the corresponding value CB, or may be table data indicating the correspondence relationship between the elapsed time EB and the corresponding value CB. The correspondence data DB is set to have the breaker characteristics shown by the graph G1 in FIG. 2.

[0041] When the current value flowing through the relay 11 exceeds the threshold B, the control unit 14 repeatedly calculates the time integral value ZB of the current value after exceeding the threshold B. For example, as shown in FIG. 4, the control unit 14 first calculates ZB1 as the time integral value ZB. In the next period, the control unit 14 adds ZB2 to the time integral value ZB calculated in the previous period to obtain a new time integral value ZB. The control unit 14 repeatedly calculates the time integral value ZB by repeating such processing. The control unit 14 uses the correspondence data DB to derive the corresponding value CB corresponding to the elapsed time EB. The control unit 14 repeatedly determines whether the time integral value ZB has exceeded the corresponding value CB. In the example shown in FIG. 4, the time integral value ZB in the sixth period to which ZB6 is added exceeds the corresponding value CB. When the control unit 14 determines that the time integral value ZB has exceeded the corresponding value CB, the control unit 14 switches the breaker unit 12 to the breaker state.

[0042] The time integral value ZB may be reset to 0 when a second reset condition is satisfied. The second reset condition may be that a certain time has elapsed since the value of the current flowing through relay 11 exceeded threshold value B, or that the value of the current flowing through relay 11 has fallen below threshold value B, or may be another condition.

[0043] The second control unit 15 controls the relay 11. The second control unit 15 is configured as, for example, an MCU (Micro Controller Unit). The second control unit 15 is configured as a device separate from the control unit 14. The second control unit 15 switches the relay 11 to an on state when a predetermined start condition is met. The start condition is, for example, that the start switch of the vehicle is switched to an on state. The start switch is, for example, an ignition switch in an engine vehicle, a power switch in an electric vehicle, etc. The second control unit 15 recognizes the on / off state of the start switch of the vehicle, for example, by receiving a signal indicating the on / off state of the start switch of the vehicle. The second control unit 15 switches the relay 11 to an off state when a predetermined stop condition is met. The stop condition is, for example, that the start switch of the vehicle is switched to an off state. The second control unit 15 switches the relay 11 to an off state when a predetermined cut-off condition is met. The cut-off condition is, for example, a condition that can be met based on the current value flowing through the relay 11. An example of a condition that may be satisfied based on the value of the current flowing through relay 11 is that the value of the current flowing through relay 11 exceeds a reference value. Second control unit 15 detects the value of the current flowing through relay 11 based on the signal output from current detection unit 13.

[0044] When the value of the current flowing through the relay 11 exceeds a reference value, the second control unit 15 switches the relay 11 to the OFF state based on the elapsed time EC since the current value exceeded the reference value and the current value after the current value exceeded the reference value.

[0045] When the current value flowing through the relay 11 exceeds the reference value, the second control unit 15 judges whether or not the time integral value ZC of the current value after exceeding the reference value exceeds the corresponding value CC corresponding to the elapsed time EC, and switches the relay 11 to the OFF state when it is judged that the time integral value ZC has exceeded the corresponding value CC. The second control unit 15 prestores the corresponding data DC indicating the correspondence relationship between the elapsed time EC and the corresponding value CC. The corresponding data DC may be a function indicating the correspondence relationship between the elapsed time EC and the corresponding value CC, or may be table data indicating the correspondence relationship between the elapsed time EC and the corresponding value CC. The corresponding data DC is set to have the interruption characteristics shown by the graph G2 in FIG. 2. The graph G2 indicates the time until interruption when the current of the current value continues to flow for each current value in a predetermined current value range (specifically, a current value range smaller than the lower limit value of the current value range in the graph G1). The graph G2 indicates the characteristic that the larger the current value, the shorter the time required for interruption.

[0046] When the current value flowing through the relay 11 exceeds the reference value, the second control unit 15 repeatedly calculates the time integral value ZC of the current value after exceeding the reference value. For example, as shown in FIG. 5, the second control unit 15 first calculates ZC1 as the time integral value ZC. In the next period, the second control unit 15 adds ZC2 to the time integral value ZC calculated in the previous period to obtain a new time integral value ZC. The second control unit 15 repeatedly calculates the time integral value ZC by repeating such processing. The second control unit 15 uses the corresponding data DC to derive the corresponding value CC corresponding to the elapsed time EC. The second control unit 15 repeatedly determines whether the time integral value ZC has exceeded the corresponding value CC. In the example shown in FIG. 5, the time integral value ZC in the ninth period to which ZC9 is added exceeds the corresponding value CC. When the second control unit 15 determines that the time integral value ZC has exceeded the corresponding value CC, the second control unit 15 switches the breaker unit 12 to the breaker state.

[0047] The time integral value ZC may be reset to 0 when a third reset condition is met. The third reset condition may be that a certain time has elapsed since the value of the current flowing through relay 11 exceeded a reference value, or that the value of the current flowing through relay 11 has fallen below a reference value, or may be another condition.

[0048] When the current value flowing through the relay 11 exceeds a preset interruption upper limit ID, the control unit 14 switches the interruption unit 12 to the interruption state regardless of the above-mentioned elapsed times EA and EB. The interruption upper limit ID is greater than the thresholds A and B. The interruption upper limit ID is greater than the maximum interruptible current IB. The interruption upper limit ID is less than the maximum current that can be passed IC. The maximum current that can be passed IC is the maximum current that can be maintained by the relay 11 in the on state. As described above, the relay 11 is an electromagnetic relay. When a current flows through the electromagnetic relay, an electromagnetic repulsive force is generated in the electromagnetic relay so as to change the electromagnetic relay from the on state to the off state. This electromagnetic repulsive force becomes larger according to the increase in the magnitude of the current flowing into the electromagnetic relay. When the current flowing into the electromagnetic relay becomes greater than the maximum current that can be passed IC, the electromagnetic repulsive force becomes greater than the force that maintains the electromagnetic relay in the on state, and the electromagnetic relay changes to the off state. When the electromagnetic relay changes to the off state, an arc is generated in the electromagnetic relay, which may cause the electromagnetic relay to break down. Therefore, when the current value flowing through the relay 11 exceeds the interruption upper limit value ID, which is set to a value smaller than the maximum current IC that can be passed, the control unit 14 switches the interruption unit 12 to the interruption state regardless of the above-mentioned elapsed times EA and EB.

[0049] The above-mentioned maximum current IC that can be passed is smaller than the saturation current IS that flows through the power path 80 when the power path 80 has a ground fault. The saturation current IS is a saturation current when it is assumed that a ground fault occurs in the path between the relay 11 and the load 91 when the power supply unit 90 is fully charged and the in-vehicle system 100 is not degraded. The interruption upper limit ID is set so that the interruption unit 12 switches to the interruption state before the current flowing through the relay 11 reaches the saturation current IS, taking into consideration the time lag TL from when it is determined that the current flowing through the relay 11 has exceeded the interruption upper limit ID to when the interruption unit 12 switches to the interruption state.

[0050] The tripping upper limit value ID is set based on, for example, the time lag TL and TC correspondence data DD (see FIG. 6) indicating the correspondence relationship between the time elapsed since the occurrence of a ground fault and the value of the current flowing through the relay 11.

[0051] The time lag TL is generated by the time from when the control unit 14 determines that the cutoff upper limit ID has been exceeded to when it starts control to switch the cutoff unit 12 to the cutoff state, and the time from when it starts control to switch the cutoff unit 12 to the cutoff state to when the cutoff unit 12 switches to the cutoff state. The time lag TL can be obtained, for example, from test results or simulation results.

[0052] The TC corresponding data DD is obtained, for example, from a test result or a simulation result. The test result or the simulation result is, for example, a result when a ground fault occurs in the path between the relay 11 and the load 91 when the in-vehicle system 100 is not deteriorated and the power supply unit 90 is fully charged.

[0053] In the TC corresponding data DD shown in Fig. 6, a ground fault occurs at time T0. After that, the current value gradually increases with time. At time T4, the current value flowing through the relay 11 becomes the saturation current IS.

[0054] The timing at which it is determined that the current value flowing through the relay 11 has reached the saturation current IS may be, for example, the timing when the time elapsed since the occurrence of a ground fault becomes three times the time constant τ, or the timing when 1 ms has elapsed since the occurrence of a ground fault. The time constant τ is calculated, for example, by the following formula (1). Time constant τ=(L1+L2+L3) / (R1+R2+R3)...Equation (1) L1 is the internal inductance of the power supply unit 90. L2 is the inductance of the path between the power supply unit 90 and the ground fault location in the power path 80. L3 is the inductance of the ground fault location. R1 is the internal resistance value of the power supply unit 90. R2 is the resistance value of the path between the power supply unit 90 and the ground fault location in the power path 80. R3 is the resistance value of the ground fault location. Note that L3 and R3 may change depending on the manner of the ground fault, and may therefore be set to 0, for example.

[0055] For example, the current value corresponding to the timing T1 that does not reach the timing T4 even when the time lag TL is taken into consideration is set as the shutoff upper limit ID. In other words, the timing T1 at which the timing T2 after the time lag TL elapses is earlier than the timing T4 is specified, and the current value corresponding to this timing T1 is set as the shutoff upper limit ID.

[0056] The interruption upper limit value ID is set in consideration of the time lag TL from when it is determined that the current value flowing through the relay 11 exceeds the interruption upper limit value ID until the interrupter 12 switches to the interruption state, so that the interrupter 12 switches to the interruption state before the current value flowing through the relay 11 reaches the maximum allowable current IC. The interruption upper limit value ID is set, for example, based on the time lag TL and the above-mentioned TC corresponding data DD.

[0057] In the TC correspondence data DD shown in Fig. 6, the timing when the current value flowing through the relay 11 reaches the maximum current IC that can be passed is set to be timing T3. For example, the current value corresponding to timing T1 that does not reach timing T3 even when time lag TL is taken into consideration is set as the tripping upper limit ID. In other words, timing T1 at which timing T2 after time lag TL elapses is earlier than timing T3 is specified, and the current value corresponding to this timing T1 is set as the tripping upper limit ID.

[0058] The shutoff upper limit ID is set to a value greater than the maximum current value IE that can flow through the power path 80 when the power path 80 is in a normal state. The normal state of the power path 80 refers to a state in which the power path 80 is not faulted to ground, and more specifically, a state in which the voltage value of the power path 80 is equal to or greater than a threshold voltage. The threshold voltage is a value of 0 V or greater. The maximum current value IE that can flow through the power path 80 refers to, for example, the current that flows through the power path 80 when a load 91, such as a motor in a vehicle, is operated to its maximum capacity when the power source unit 90 is fully charged.

[0059] When the control unit 14 determines that the second control unit 15 has controlled the relay 11 to the off state while the value of the current flowing through the relay 11 exceeds the threshold A, the control unit 14 switches the breaker unit 12 to the off state regardless of the elapsed time EA. When the control unit 14 determines that the second control unit 15 has controlled the relay 11 to the off state while the value of the current flowing through the relay 11 exceeds the threshold B, the control unit 14 switches the breaker unit 12 to the off state regardless of the elapsed time EB. The second control unit 15 outputs, for example, a control signal for controlling the relay 11 to the off state and also outputs a notification signal to the control unit 14. By receiving the notification signal, the control unit 14 determines that the second control unit 15 has controlled the relay 11 to the off state.

[0060] The control unit 14 performs the process shown in Fig. 7 when, for example, the start switch of the vehicle is switched to the OFF state. In step S11, the control unit 14 determines whether or not the value of the current flowing through the relay 11 is greater than threshold A. If the control unit 14 determines that the value of the current flowing through the relay 11 is not greater than threshold A, then in step S14, the control unit 14 determines whether or not the value of the current flowing through the relay 11 is greater than threshold B. If the control unit 14 determines that the value of the current flowing through the relay 11 is not greater than threshold B, the control unit 14 returns to step S11. If the value of the current flowing through the relay 11 is normal, the control unit 14 repeats the processes of steps S11 and S14.

[0061] For example, if a ground fault occurs between the relay 11 and the load 91, the current value flowing through the relay 11 increases. When the control unit 14 determines in step S11 that the current value flowing through the relay 11 is greater than the threshold value A, the control unit 14 starts calculating the time integral value ZA and proceeds to step S12. Note that, when the control unit 14 has already calculated the time integral value ZA, the control unit 14 continues calculating the time integral value ZA. When the control unit 14 determines that the time integral value ZA is greater than the corresponding value CA, the control unit 14 switches the breaker unit 12 to the breaker state in step S13. When the control unit 14 determines that the time integral value ZA is not greater than the corresponding value CA, the control unit 14 proceeds to step S14.

[0062] When the control unit 14 determines in step S14 that the current value flowing through the relay 11 is greater than the threshold value B, the control unit 14 starts calculating the time integral value ZB and proceeds to step S15. Note that, when the control unit 14 has already calculated the time integral value ZB, the control unit 14 continues calculating the time integral value ZB. When the control unit 14 determines in step S15 that the time integral value ZB is greater than the corresponding value CB corresponding to the time integral value ZB, the control unit 14 determines in step S16 whether the control unit 14 has controlled the relay 11 to the OFF state. When the control unit 14 determines that the control unit 14 has not controlled the relay 11 to the OFF state, the control unit 14 determines in step S17 whether the current value flowing through the relay 11 is greater than the interrupt upper limit value ID. When the control unit 14 determines that the current value flowing through the relay 11 is not greater than the interrupt upper limit value ID, the control unit 14 returns to step S11. That is, when the value of the current flowing through the relay 11 exceeds the threshold value B, the control unit 14 repeats the processes of steps S14, S15, S16, and S17.

[0063] If the control unit 14 determines in step S15 that the time integral value ZB is greater than the corresponding value CB, the control unit 14 switches the breaker unit 12 to the breaker state in step S13. If the control unit 14 determines in step S16 that the control unit 14 has controlled the relay 11 to the off state, the control unit 14 switches the breaker unit 12 to the breaker state in step S13. If the control unit 14 determines in step S17 that the value of the current flowing through the relay 11 is greater than the breaker upper limit value ID, the control unit 14 switches the breaker unit 12 to the breaker state in step S13.

[0064] The following description relates to the effects of the in-vehicle control device 10. The in-vehicle control device 10 switches the breaker 12 to the cut-off state based on the elapsed time EA since the current value flowing through the relay 11 exceeded the threshold A and the current value after exceeding the threshold A. That is, the in-vehicle control device 10 can switch the breaker 12 to the cut-off state taking into consideration the elapsed time EA since the current value flowing through the relay 11 exceeded the threshold A and the current value after exceeding the threshold A. The in-vehicle control device 10 can also switch the breaker 12 to the cut-off state when the time integral value ZA of the current value is accumulated to an extent that it exceeds a corresponding value CA corresponding to the elapsed time EA.

[0065] The in-vehicle control device 10 switches the breaker unit 12 to the cut-off state based on the elapsed time EB since the current value flowing through the relay 11 exceeded the threshold B and the current value after exceeding the threshold B. That is, the in-vehicle control device 10 can switch the breaker unit 12 to the cut-off state taking into consideration the elapsed time EB since the current value flowing through the relay 11 exceeded the threshold B and the current value after exceeding the threshold B. In addition, the in-vehicle control device 10 can switch the breaker unit 12 to the cut-off state when the time integral value ZB of the current value is accumulated to an extent that it exceeds a corresponding value CB corresponding to the elapsed time EB.

[0066] When the current value flowing through the relay 11 exceeds the upper cut-off value ID, the vehicle control device 10 switches the cut-off unit 12 to the cut-off state regardless of the elapsed time EB, making it easier to switch the cut-off unit 12 to the cut-off state before the relay 11 can no longer maintain the on state.

[0067] The vehicle-mounted control device 10 can switch the cutoff unit 12 to the cutoff state before the value of the current flowing through the relay 11 reaches the saturation current IS.

[0068] The vehicle control device 10 can switch the cutoff unit 12 to the cutoff state before the value of the current flowing through the relay 11 reaches the maximum current IC that can be passed through the relay 11. Therefore, the vehicle control device 10 can prevent the relay 11 from being unable to maintain the on state due to a current that exceeds the maximum current IC passing through the relay 11.

[0069] It is also assumed that even if the second control unit 15 attempts to switch the relay 11 to the OFF state based on the elapsed time EC and the current value, the relay 11 may not be switched to the OFF state due to a failure of the relay 11. Even if such a situation occurs, the in-vehicle control device 10 can more reliably interrupt the current flowing through the power path 80 by switching the interrupter 12 to the interruption state when the second control unit 15 attempts to switch the relay 11 to the OFF state.

[0070] <Other embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, the features of the above or later described embodiments can be combined in any combination within a range that does not contradict. In addition, any feature of the above or later described embodiments can be omitted unless it is clearly stated as essential. Furthermore, the above-mentioned embodiment may be modified as follows.

[0071] In the above embodiment, the control unit 14 is configured to determine whether or not the time integral value ZA of the current value after exceeding the threshold A exceeds the corresponding value CA corresponding to the elapsed time EA when the current value flowing through the relay 11 exceeds the threshold A and to switch the breaker unit 12 to the breaker state when it is determined that the time integral value ZA of the current value after exceeding the threshold A exceeds the corresponding value ... exceeds the corresponding value. In this case, the in-vehicle control device can switch the breaker unit 12 to the breaker state when the time integral value of the square of the current value accumulates to an extent that it exceeds the corresponding value corresponding to the elapsed time EA.

[0072] In the above embodiment, the control unit 14 is configured to determine whether or not the time integral value ZA of the current value after exceeding the threshold B exceeds the corresponding value CB corresponding to the elapsed time EB when the current value flowing through the relay 11 exceeds the threshold B, and to switch the breaker unit 12 to the breaker state when it is determined that the time integral value ZA of the current value after exceeding the threshold B exceeds the corresponding value corresponding to the elapsed time EB ... corresponding value corresponding to the elapsed time EB when it is determined that the time integral value ZA of the current value after exceeding the corresponding value corresponding to the elapsed time EB when it is determined that the time integral value ZA of the current value after exceeding the corresponding value corresponding to the elapsed time EB when it is determined that the time integral value ZA of the current value after exceeding the corresponding value corresponding to the elapsed time EB when it is determined that the time integral value ZA of the current value after exceeding the corresponding value corresponding to the elapsed time EB when it is determined that the time integral

[0073] The cutoff upper limit value does not have to be set, that is, the process of step S16 in FIG.

[0074] One of threshold A and threshold B may be omitted. That is, one of steps S11, S12 and steps S14, S15 in FIG.

[0075] In the above embodiment, the interruption upper limit ID is greater than the maximum interruptible current IB, but it may be smaller than the maximum interruptible current IB.

[0076] A fuse may be provided between the power supply unit 90 and the current detection unit 13 .

[0077] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope indicated by the claims or within the scope equivalent to the claims. [Explanation of symbols]

[0078] 10...In-vehicle control device 11…Relay 12...Cutting section 13...Current detection section 14...Control section 15...Second control section 80…Power line 90...Power supply section 91...Load 100…In-vehicle systems A…Threshold B: Threshold DA: Corresponding data DB…Supported data DC…Corresponding data DD...TC compatible data EA: Elapsed time EB…Elapsed time EC: Elapsed time G1…Graph G2…Graph IB: Maximum current that can be interrupted IC…Maximum current that can be passed ID: Upper limit of cutoff IE: Maximum current that can flow through the power line IS…Saturation current TL: Time lag ZA: Time integral value ZB: Time integral value ZC: Time integral value

Claims

1. An in-vehicle control device included in an in-vehicle system including a power path for supplying power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, the control unit, when a value of the current flowing through the relay exceeds a threshold, switches the interrupting unit to the interrupting state based on a time elapsed since the current value exceeded the threshold and the current value after the current value exceeded the threshold; The threshold value is a value smaller than a maximum interruptable current, which is a maximum current at which the relay can be switched from an on state to an off state. In-vehicle control device.

2. An in-vehicle control device included in an in-vehicle system including a power path for supplying power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, the control unit, when a value of the current flowing through the relay exceeds a threshold, switches the interrupting unit to the interrupting state based on a time elapsed since the current value exceeded the threshold and the current value after the current value exceeded the threshold; When the current value exceeds the threshold, the control unit determines whether or not a time integral value of the current value after exceeding the threshold exceeds a corresponding value corresponding to the elapsed time, and switches the cutoff unit to the cutoff state when it is determined that the time integral value of the current value has exceeded the corresponding value. In-vehicle control device.

3. An in-vehicle control device included in an in-vehicle system including a power path for supplying power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, the control unit, when a value of the current flowing through the relay exceeds a threshold, switches the interrupting unit to the interrupting state based on a time elapsed since the current value exceeded the threshold and the current value after the current value exceeded the threshold; When the current value exceeds the threshold, the control unit determines whether or not a time integral of a square of the current value after the current value exceeds the threshold exceeds a corresponding value corresponding to the elapsed time, and switches the cutoff unit to the cutoff state when it is determined that the corresponding value has been exceeded. In-vehicle control device.

4. An in-vehicle control device included in an in-vehicle system including a power path for supplying power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, the control unit, when a value of the current flowing through the relay exceeds a threshold, switches the interrupting unit to the interrupting state based on a time elapsed since the current value exceeded the threshold and the current value after the current value exceeded the threshold; A blocking upper limit value that is greater than the threshold value and smaller than a maximum current that can be passed, which is a maximum current at which the relay can maintain an on-state, is set in advance, When the current value exceeds the cut-off upper limit, the control unit switches the cut-off unit to the cut-off state regardless of the elapsed time. In-vehicle control device.

5. The maximum current that can be passed is smaller than a saturation current that flows through the power path when the power path has a ground fault, The cut-off upper limit value is set in consideration of a time lag from when it is determined that the current value has exceeded the cut-off upper limit value until the cut-off unit switches to the cut-off state, so that the cut-off unit switches to the cut-off state before the current value reaches the saturation current. The vehicle-mounted control device according to claim 4.

6. The cut-off upper limit value is set in consideration of a time lag from when it is determined that the current value has exceeded the cut-off upper limit value until the cut-off unit switches to the cut-off state, so that the cut-off unit switches to the cut-off state before the current value reaches the maximum current that can be passed. The vehicle-mounted control device according to claim 4.

7. An in-vehicle control device included in an in-vehicle system including a power path for supplying power from a power supply unit to a load, a relay provided in the power path, and a breaker provided in the power path, A control unit that controls the interrupter, the cutoff unit switches from a permissive state in which power is permitted to be supplied from the power supply unit side to the load side to a cutoff state in which power is cut off, the control unit, when a value of the current flowing through the relay exceeds a threshold, switches the interrupting unit to the interrupting state based on a time elapsed since the current value exceeded the threshold and the current value after the current value exceeded the threshold; The relay is controlled by a second control unit different from the control unit, When the control unit determines that the second control unit has controlled the relay to an off state while the current value exceeds the threshold value, the control unit switches the interrupter to the interruption state regardless of the elapsed time. In-vehicle control device.

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