On-vehicle device, information processing method, and program

Abstract

To provide an on-vehicle device etc. for changing cutoff characteristics of a semiconductor fuse according to a power consumption state of a vehicle.SOLUTION: An on-vehicle device that performs opening / closing control of a plurality of semiconductor fuses installed in a power supply line from a power supply device mounted in a vehicle, includes a control unit that performs processing related to the opening / closing control of the semiconductor fuses. The semiconductor fuses include a main-line semiconductor fuse disposed in a main line and a branch-line semiconductor fuse disposed in each of a plurality of branch lines branched from the main line. The control unit acquires information on a power consumption state of the vehicle, and according to the acquired information on the power consumption state of the vehicle, validates a protection function of the main-line semiconductor fuse, and invalidates the protection function of the branch-line semiconductor fuse.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present technology relates to an in-vehicle device, an information processing method, and a program. [Background technology]

[0002] A vehicle is equipped with a power supply control device (see, for example, Patent Document 1) that controls power supply from a battery to a load. In the power supply control device described in Patent Document 1, a downstream semiconductor fuse is provided in a current path of a current flowing from the battery to the load, and the power supply from the battery to the load is controlled by switching the downstream semiconductor fuse on or off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-143905 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the power supply control device described in Patent Document 1 does not take into consideration changing the interruption characteristics of the semiconductor fuse in accordance with the power consumption state of the vehicle.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide an in-vehicle device or the like that can change the interrupting characteristics of a semiconductor fuse in accordance with the power consumption state of the vehicle. [Means for solving the problem]

[0006] An in-vehicle device according to one embodiment of the present disclosure is an in-vehicle device that controls the opening and closing of multiple semiconductor fuses provided in a power line from a power supply device mounted on a vehicle, and is equipped with a control unit that performs processing related to the opening and closing control of the semiconductor fuses, wherein the semiconductor fuses include a main line semiconductor fuse arranged in the main line and branch line semiconductor fuses arranged in each of multiple branch lines branched off from the main line, and the control unit acquires information regarding the power consumption state of the vehicle, and enables a protection function of the main line semiconductor fuse and disables the protection function of the branch line semiconductor fuse according to the acquired information regarding the power consumption state of the vehicle. Effect of the Invention

[0007] According to one aspect of the present disclosure, it is possible to provide an in-vehicle device or the like that changes the interrupting characteristics of a semiconductor fuse depending on the power consumption state of the vehicle. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating a configuration of an in-vehicle system including an in-vehicle device according to a first embodiment. [Diagram 2] 2 is a block diagram illustrating an example of an internal configuration of an in-vehicle device; [Diagram 3] FIG. 4 is an explanatory diagram for explaining the setting of the interruption characteristics of the main line semiconductor fuse. [Figure 4] 4 is a flowchart illustrating a process of a control unit of an in-vehicle device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiment of the present invention] First, embodiments of the present disclosure will be listed and described. In addition, at least some of the embodiments described below may be arbitrarily combined.

[0010] (1) An in-vehicle device according to one embodiment of the present disclosure is an in-vehicle device that controls the opening and closing of multiple semiconductor fuses provided in a power line from a power supply device mounted on a vehicle, and includes a control unit that performs processing related to the opening and closing control of the semiconductor fuses, wherein the semiconductor fuses include a main line semiconductor fuse arranged in a main line and branch line semiconductor fuses arranged in each of multiple branch lines branched off from the main line, and the control unit acquires information regarding a power consumption state of the vehicle, and enables a protection function of the main line semiconductor fuses and disables the protection function of the branch line semiconductor fuses in accordance with the acquired information regarding the power consumption state of the vehicle.

[0011] In this aspect, the control unit of the in-vehicle device performs opening and closing control of a semiconductor fuse provided in a power line from the power supply device, and when an overcurrent flows in the power line, the control unit turns off (opens) the semiconductor fuse according to the interruption characteristics determined by the semiconductor fuse to interrupt the overcurrent. When an in-vehicle load such as an actuator is connected to the semiconductor fuse, the control unit of the in-vehicle device may perform on-off control (opening and closing control) of the semiconductor fuse according to a drive request for the in-vehicle load. The semiconductor fuse includes a main line semiconductor fuse arranged in the main line and branch line semiconductor fuses arranged in each of a plurality of branch lines branched from the main line. In the flow direction of current from the power supply device, the main line semiconductor fuse is located upstream, and each of the plurality of branch line semiconductor fuses is located downstream of the main line semiconductor fuse. When an overcurrent flows for a predetermined period or more, the semiconductor fuses including the main line semiconductor fuse and the branch line semiconductor fuse are turned off (opened) by the control unit according to the set interruption characteristics, thereby exerting a protective function of interrupting the overcurrent. Furthermore, the semiconductor fuses including the main line semiconductor fuses and the branch line semiconductor fuses may be opened or closed (on / off controlled) by the control unit to start or stop power supply to the vehicle loads connected to the semiconductor fuses, thereby controlling the drive of the vehicle loads (exercising a drive control function). The control unit of the vehicle-mounted device may obtain information on the power consumption state of the vehicle by obtaining, for example, a signal from an IG switch or a power switch that controls the start and stop of the vehicle. Alternatively, the control unit of the vehicle-mounted device may obtain information on the power consumption state of the vehicle by obtaining, for example, information on the vehicle speed, information on the rotation of the engine or the drive motor, from an in-vehicle ECU connected to the in-vehicle network. In this way, the power consumption state of the vehicle may indicate a state related to the power consumed in the vehicle depending on whether the vehicle is in a running state (started state) or a parked state (stopped state).The control unit of the in-vehicle device enables (activates) the protection function of the main line semiconductor fuse and disables (deactivates) the protection function of each of the branch line semiconductor fuses arranged in each of the multiple branch lines based on information on the power consumption state of the vehicle. In other words, by using the protection function of the main line semiconductor fuse to protect the main line and the multiple branch lines branched off from the main line, that is, while ensuring safety as an in-vehicle system, according to the power consumption state of the vehicle, it is possible to reduce the dark current required to exercise the protection function of the branch line semiconductor fuse by disabling each of the branch line semiconductor fuses. This makes it possible to reduce the power consumption of the vehicle, especially in a standby state (low current consumption mode) such as when parked.

[0012] (2) In an in-vehicle device according to one embodiment of the present disclosure, when the control unit activates the protective function of the main line semiconductor fuse, it sets the interruption characteristics of the main line semiconductor fuse so that the interruption characteristics are below the smoke generation characteristics corresponding to the plurality of branch lines and exceed the sum of the current values ​​flowing through the plurality of branch lines when the vehicle is in a standby state.

[0013] In this aspect, when enabling the protection function of the main line semiconductor fuse, the control unit of the in-vehicle device sets the interruption characteristic of the main line semiconductor fuse to be lower than the smoke generation characteristic corresponding to the plurality of branch lines and to be higher than the sum (combined value) of the current values ​​flowing through the plurality of branch lines when the vehicle is in a standby state. The smoke generation characteristic corresponding to the plurality of branch lines is, for example, a smoke generation characteristic obtained by combining the smoke generation characteristics of each of the branch lines. Alternatively, the smoke generation characteristic corresponding to the plurality of branch lines may be a smoke generation characteristic obtained by combining the smoke generation characteristics of each of the in-vehicle loads (devices), such as sensors or actuators, connected to each of the branch lines. The sum (combined value) of the current values ​​flowing through the plurality of branch lines when the vehicle is in a standby state may be a predetermined assumed value that is used (applied) as the maximum value of the current value flowing through the main line in the standby state. For example, when the interruption characteristics of the main line semiconductor fuse are set to an initial value (initial setting) or to a setting corresponding to a normal state (normal current mode) in which a relatively large current flows through the main line, the control unit of the in-vehicle device may change the interruption characteristics from the initial setting so that the interruption characteristics are below the smoke generation characteristics and above the sum (combined value) of the current values. It is assumed as a product specification that the lower limit of the current value determined according to the smoke generation characteristics corresponding to the multiple branch lines corresponds to, for example, about 10 times the sum (combined value) of the current values ​​flowing through the multiple branch lines when the vehicle is in standby. In such a case, the setting range of the interruption characteristics of the main line semiconductor fuse can be made relatively wide by setting the smoke generation characteristics corresponding to the multiple branch lines as the upper limit and the sum (combined value) of the current values ​​flowing through the multiple branch lines when the vehicle is in standby as the lower limit. In this case, the interruption characteristics of the main line semiconductor fuse in the standby state (low current consumption mode) may be set to a mid-range value between the smoke generation characteristics corresponding to the multiple branch lines and the sum (combined value) of the current values ​​flowing through the multiple branch lines when the vehicle is in the standby state.Therefore, for example, by setting the interruption characteristics of the main line semiconductor fuse to near the intermediate value (mid-range), the degree of influence of errors in the on-resistance of the main line semiconductor fuse or in the current value detection when performing interruption control can be reduced, resulting in a relatively robust control mode, and the safety of the in-vehicle system can be efficiently ensured.

[0014] (3) In an in-vehicle device according to one embodiment of the present disclosure, the power consumption state of the vehicle includes a normal state and a standby state that consumes less power than the normal state, and when the acquired information regarding the power consumption state of the vehicle indicates the standby state, the control unit enables a protection function of the main line semiconductor fuse and disables the protection function of the branch line semiconductor fuse, and when the acquired information regarding the power consumption state of the vehicle indicates the normal state, disables the protection function of the main line semiconductor fuse and enables the protection function of the branch line semiconductor fuse.

[0015] In this embodiment, the power consumption state of the vehicle includes a normal state and a standby state (low current consumption mode) in which power consumption is less than that in the normal state (normal current mode). The normal state may include, for example, a state in which the vehicle is running (starting up) and may indicate a state in which the power consumption of the vehicle is equal to or greater than a predetermined value (normal current mode). The standby state may include, for example, a state in which the vehicle is parked (stopped) and may indicate a state in which the power consumption of the vehicle is less than a predetermined value (low current consumption mode). When the acquired information on the power consumption state of the vehicle indicates the normal state (when the vehicle is in the normal state), the control unit disables the protection function of the main line semiconductor fuse and enables the protection function of the branch line semiconductor fuse. When the acquired information on the power consumption state of the vehicle indicates the normal state (when the vehicle is in the standby state), the control unit disables the protection function of the main line semiconductor fuse and enables the protection function of the branch line semiconductor fuse. In this way, by complementarily enabling or disabling the main line semiconductor fuse and the branch line semiconductor fuse according to the power consumption state of the vehicle (normal state or standby state), it is possible to reduce the power consumption required for controlling the disabled semiconductor fuse (main line semiconductor fuse or branch line semiconductor fuse). By providing a main line semiconductor fuse and a branch line semiconductor fuse that are subjected to such complementarily control, it is possible to improve the design freedom or implementation freedom of the configuration that reduces dark current in a standby state (low current consumption mode) such as while parked.

[0016] (4) An in-vehicle device according to one embodiment of the present disclosure includes a mechanical relay connected in parallel to the main line semiconductor fuse, and the control unit maintains the mechanical relay in an open state when the vehicle is in standby.

[0017] In this embodiment, the in-vehicle device includes a mechanical relay connected in parallel to the semiconductor fuse for the main line. That is, a main line forming a part of a power supply line extended from a power supply device such as a lead battery includes a main line in which a semiconductor fuse is arranged and a main line in which a mechanical relay is arranged, and a parallel circuit is formed by the main line of the semiconductor fuse and the main line of the mechanical relay. A fuse (melting type fuse) may also be arranged in the main line in which the mechanical relay is arranged. In this case, the mechanical relay and the fuse (melting type fuse) are connected in series in the main line. When the vehicle is in a standby state (low current consumption mode) such as while parked, the control unit of the in-vehicle device maintains the mechanical relay in an open state (off), making it possible to eliminate the need for opening and closing the mechanical relay in the standby state, thereby improving the number of times of durability (usable period, parts life) of the mechanical relay.

[0018] (5) In an in-vehicle device according to one embodiment of the present disclosure, the control unit acquires a current value flowing through the main line in which the main line semiconductor fuse is disposed, and performs interruption control on the main line semiconductor fuse, the interruption characteristics of which are set according to the standby state, based on the acquired current value.

[0019] In this aspect, the control unit of the in-vehicle device acquires a current value flowing through the main line from a current detection unit that detects a current flowing through the main line on which the main line semiconductor fuse is arranged. The current detection unit is, for example, configured with a shunt resistor provided on the main line on which the main line semiconductor fuse is arranged. Alternatively, when the main line semiconductor fuse is configured with, for example, an IPD (Intelligent Power Device), the current detection unit built into the IPD may be used. The control unit of the in-vehicle device performs interruption control on the main line semiconductor fuse based on the current value detected by the current detection unit and in accordance with interruption characteristics set according to the standby state. The interruption characteristics may be shown as an interruption characteristic curve in a characteristic graph with the vertical axis representing the current value (A) and the horizontal axis representing the elapsed time (S), and the interruption characteristic curve may be stored in a storage unit. The control unit of the in-vehicle device refers to the interruption characteristic curve stored in the memory unit, and cuts off the current (overcurrent) flowing through the main line by opening (turning off) the main line semiconductor fuse according to the current value detected by the current detection unit and the elapsed time. In a standby state (low current consumption mode) such as while the vehicle is parked, even if the protective functions of the branch line semiconductor fuses directly connected to the in-vehicle device such as individual actuators are disabled, interruption control can be performed using the main line semiconductor fuses whose interruption characteristics are set according to the standby state. This makes it possible to efficiently ensure the safety of the in-vehicle system while reducing the dark current in the standby state (low current consumption mode).

[0020] (6) A program according to one embodiment of the present disclosure is a program that causes a computer to execute processing to control the opening and closing of multiple semiconductor fuses provided in a power line from a power supply device mounted in a vehicle, the semiconductor fuses including a main line semiconductor fuse arranged in the main line and branch line semiconductor fuses arranged in each of multiple branch lines branched off from the main line, and acquires information regarding a power consumption state of the vehicle, and executes processing to enable a protection function of the main line semiconductor fuses and disable the protection function of the branch line semiconductor fuses in accordance with the acquired information regarding the power consumption state of the vehicle.

[0021] In this aspect, a program can be provided that causes a computer to function as an on-board device that changes the interrupting characteristics of the main line semiconductor fuse in accordance with the power consumption state of the vehicle.

[0022] (7) An information processing method according to one aspect of the present disclosure is an information processing method that causes a computer to execute processing to control the opening and closing of multiple semiconductor fuses provided in a power line from a power supply device mounted on a vehicle, the semiconductor fuses including a main line semiconductor fuse arranged in a main line and branch line semiconductor fuses arranged in each of multiple branch lines branched off from the main line, and acquires information regarding a power consumption state of the vehicle, and executes processing to enable a protection function of the main line semiconductor fuses and disable the protection function of the branch line semiconductor fuses in accordance with the acquired information regarding the power consumption state of the vehicle.

[0023] In this aspect, it is possible to provide an information processing method for causing a computer to function as an on-board device that changes the interrupting characteristics of a main line semiconductor fuse in accordance with the power consumption state of the vehicle.

[0024] [Details of the embodiment of the present disclosure] The present disclosure will be specifically described based on the drawings showing the embodiments. An in-vehicle device 1 according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0025] (Embodiment 1) Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of an in-vehicle system S including an in-vehicle device 1 according to the first embodiment. FIG. 2 is a block diagram illustrating an internal configuration of the in-vehicle device 1. The in-vehicle system S is composed of the in-vehicle device 1 mounted on a vehicle C, an in-vehicle ECU 2, and an in-vehicle network 3 that communicatively connects them. The in-vehicle network 3 is composed of a plurality of communication lines 31. When communication in the in-vehicle network 3 is performed according to a communication protocol such as CAN (Controller Area Network) or CAN-FD, the communication line 31 corresponds to a CAN bus.

[0026] The vehicle C is equipped with a power supply device 5 configured with a lead battery, an alternator, a secondary battery, or the like. The power supply device 5 and the in-vehicle device 1 are connected by a power line 51. The power supply device 5 and the in-vehicle device 1 are not limited to being directly connected by the power line 51, and may be indirectly connected with an electric box (junction box) such as a relay box or a fuse 521 box interposed between the power supply device 5 and the in-vehicle device 1.

[0027] The in-vehicle device 1 and the multiple in-vehicle loads 6 or the in-vehicle ECU 2 are connected by a power line 51 (branch line 512), and the in-vehicle device 1 distributes power to the multiple in-vehicle loads 6 or the in-vehicle ECU 2. That is, the in-vehicle device 1 functions as a power distribution device that distributes power supplied from the power supply device 5 via the power line 51 to the multiple in-vehicle loads 6 or the in-vehicle ECU 2 arranged downstream in the direction of current flow.

[0028] The power line 51 extending from the power supply device 5 is connected to a main line semiconductor fuse 531 provided in the in-vehicle device 1. The power line 51 is located inside the in-vehicle device 1 and includes a main line 511 to which the main line semiconductor fuse 531 is connected and a plurality of branch lines 512 branched from the main line 511. The main line 511 includes a main line 511 to which the main line semiconductor fuse 531 is connected and a main line 511 to which a fuse 521 (a melting fuse) and a mechanical relay 52 are connected, and the main line 511 of the main line semiconductor fuse 531 and the main line 511 of the fuse 521 (a melting fuse) etc. form a parallel circuit. That is, the main line semiconductor fuse 531, the fuse 521 (a melting fuse) and the mechanical relay 52 are connected in parallel.

[0029] A current detection unit 513 is arranged between the main line semiconductor fuse 531 and a branch point where the main line 511 branches into a plurality of branch lines 512. The current detection unit 513 may be provided on the main line 511 on which the main line semiconductor fuse 531 is arranged. The current detection unit 513 periodically or steadily detects the value of a current (current value) flowing through the main line semiconductor fuse 531. The current detection unit 513 is a current sensor constituted by, for example, a shunt resistor, and outputs the detected current value to the control unit 11 of the in-vehicle device 1. Alternatively, the current detection unit 513 may be a current sensor (main line current sensor) built into an IPD (Intelligent Power Device) constituting the main line semiconductor fuse 531.

[0030] A branch line semiconductor fuse 532 is disposed in each of the branch lines 512. The branch line semiconductor fuse 532 is formed of, for example, an IPD (Intelligent Power Device). The branch line semiconductor fuse 532 disposed in each of the branch lines 512 is disposed downstream of the main line semiconductor fuse 531 in the direction of current flow from the power supply line 51. The branch line 512 located downstream of the branch line semiconductor fuse 532 in the direction of current flow from the power supply line 51 is connected to the in-vehicle load 6 or the in-vehicle ECU 2.

[0031] The in-vehicle loads 6 are, for example, actuators such as a car air conditioner, a lamp, or a drive motor. The in-vehicle ECU 2 includes a microcomputer having a communication function and performs a predetermined calculation process based on detection values ​​from sensors or output values ​​from various switches. These in-vehicle loads 6 and the like are started or stopped by starting or cutting off the power supply in response to the opening and closing control (on / off control) of a branch line semiconductor fuse 532 arranged in the branch line 512. The in-vehicle device 1 functions as a power supply control device that controls the starting and stopping of the in-vehicle loads 6 and the like by performing the opening and closing control (on / off control) of these branch line semiconductor fuses 532.

[0032] The in-vehicle device 1 may function as a power supply control device that controls the start or stop of the in-vehicle ECU 2, and may be a device having a relay function such as a CAN gateway. Alternatively, the in-vehicle device 1 may be an integrated ECU (vehicle computer) that controls the entire vehicle C in an integrated manner and has a relay function. Alternatively, the in-vehicle device 1 may be an individual ECU that is connected under the control of the integrated ECU and disposed in each area of ​​the vehicle C. Alternatively, the in-vehicle device 1 may be configured as a body ECU that controls body actuators of the vehicle C. Alternatively, the in-vehicle device 1 may be a PLB (Power Lan Box) that functions as a power distribution device that distributes and relays power output from a power supply device 5 such as a secondary battery and supplies power to in-vehicle devices such as actuators, in addition to relaying communication. The in-vehicle device 1 may be connected to in-vehicle devices such as various switches, sensors, or actuators.

[0033] The in-vehicle device 1 includes a control unit 11, a storage unit 12, a communication unit 13, and an input / output I / F 14. The control unit 11 is configured with a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and performs various control processes and arithmetic processes by reading and executing a control program P (program product) and data pre-stored in the storage unit 12.

[0034] The storage unit 12 is configured by a volatile memory element such as a RAM (Random Access Memory), or a non-volatile memory element such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable ROM), or a flash memory, or a combination of these storage devices, and stores a control program P (program product) and data to be referenced during processing in advance. The control program P (program product) stored in the storage unit 12 may be a control program P (program product) read from a recording medium M readable by the in-vehicle device 1. Alternatively, the control program P (program product) may be downloaded from an external computer (not shown) connected to a communication network (not shown) and stored in the storage unit 12.

[0035] The communication unit 13 is an input / output interface using a communication protocol such as CAN, CAN-FD, or Ethernet (registered trademark), and the control unit 11 communicates with the in-vehicle ECU 2 connected to the in-vehicle network 3 via the communication unit 13. In the in-vehicle device 1, a plurality of communication units 13 may be provided.

[0036] The input / output I / F 14 is, for example, a communication interface for serial communication. The input / output I / F 14 includes a plurality of terminals (output terminals), and each of the terminals is connected to a signal line 140 that is extended to the main line semiconductor fuse 531, the current detection unit 513, the mechanical relay 52, and the branch line semiconductor fuse 532. The signal line 140 is, for example, a serial cable, a wire harness, or a conductive cable (direct wire) that transmits only one signal.

[0037] The main line semiconductor fuse 531 is configured with, for example, a FET (Field Effect Transistor). Alternatively, the main line semiconductor fuse 531 may be configured with an IPD including the FET or the like. The control unit 11 of the in-vehicle device 1 performs interruption control of the main line semiconductor fuse 531 according to the interruption characteristics of the main line semiconductor fuse 531 based on the current value output from the current detection unit 513. Although details will be described later, the interruption characteristics of the main line semiconductor fuse 531 are variably set according to the power consumption state (normal state or standby state) of the vehicle C.

[0038] The branch line semiconductor fuse 532 is, for example, configured with a FET (Field Effect Transistor). Alternatively, the main line semiconductor fuse 531 may be configured with an IPD including the FET or the like. The control unit 11 of the in-vehicle device 1 performs interruption control of the branch line 512 semiconductor fuse in accordance with the interruption characteristics of the branch line 512 semiconductor fuse based on, for example, a current value output from a current sensor (branch line 512 current sensor) or the like built into the IPD constituting the branch line semiconductor fuse 532.

[0039] 3 is an explanatory diagram for explaining the setting of the interruption characteristics of the main line semiconductor fuse 531. The interruption characteristics of the main line semiconductor fuse 531 and the like and the smoke generation characteristics of the branch line 512 are both shown on a characteristics graph with the vertical axis representing current value (A) and the horizontal axis representing elapsed time (S).

[0040] The interruption characteristics define the time until a current is interrupted (corresponding to the melting time of fuse 521) when a current (overcurrent) that exceeds the rated current value of a semiconductor fuse such as main line semiconductor fuse 531 or branch line semiconductor fuse 532 flows. When the value of the current flowing through the semiconductor fuse is equal to or less than the rated current value, the semiconductor fuse does not interrupt and continues to pass a current equal to or less than the rated current value.

[0041] The main line semiconductor fuse 531 is set with an interruption characteristic corresponding to a standby state (low current consumption mode). The branch line semiconductor fuse 532 is set with an interruption characteristic corresponding to a normal state (normal current mode). The standby state (low current consumption mode) and the normal state (normal current mode) will be described in detail later.

[0042] The interruption characteristics of the main line semiconductor fuse 531 may be set by the control unit 11 of the in-vehicle device 1 as a variable characteristic value so that the current value can be shifted up and down in the vertical direction, i.e., for the same elapsed time. If the interruption characteristics of the main line semiconductor fuse 531 are high, the rated current value is also high and the time until interruption in response to an overcurrent is also long. If the interruption characteristics of the main line semiconductor fuse 531 are low, the rated current value is also low and the time until interruption in response to an overcurrent is shortened. In other words, the product of the current value (overcurrent value) and the time until interruption (integrated current value) goes up and down depending on the level of the interruption characteristics.

[0043] The interruption characteristics of the main line semiconductor fuse 531 in the standby state (fuse interruption characteristics in low current consumption mode) are set to be lower than the combined smoke characteristics (combined value) of the branch lines 512 into which the main line 511 is branched or the combined smoke characteristics (device characteristics) of the in-vehicle loads connected to the branch lines 512, for example, by applying a predetermined offset value to the combined smoke characteristics (combined value) (downstream smoke characteristics / device characteristics). Furthermore, the interruption characteristics of the main line semiconductor fuse 531 in the standby state (fuse interruption characteristics in low current consumption mode) are set to be higher than the sum of the current values ​​flowing through the branch lines 512 into which the main line 511 is branched in the standby state (for example, the combined value of power consumption during parking).

[0044] That is, the interruption characteristics of the main line semiconductor fuse 531 in the standby state (fuse interruption characteristics in the low current consumption mode) are set to be lower than the smoke generation characteristics according to the multiple branch lines 512 and to be higher than the sum (combined value) of the current values ​​flowing through the multiple branch lines 512 when the vehicle C is in the standby state. As a result, in the standby state, interruption control can be performed according to the interruption characteristics of the main line semiconductor fuse 531 without exceeding allowable values ​​defined by the smoke generation characteristics or device characteristics of the multiple branch lines 512, etc., and the multiple branch lines 512, etc. can be reliably protected from overcurrent.

[0045] The interruption characteristics of the main line semiconductor fuse 531 in the standby state thus set (fuse interruption characteristics in low current consumption mode) are set to be lower than the interruption characteristics of the fuse 521 (melt-type fuse) in the normal state (fuse interruption characteristics in normal current mode (mechanical relay)). In the normal state, the interruption characteristics of the main line semiconductor fuse 531 may be set (changed) to be the same as the interruption characteristics of the fuse 521 (melt-type fuse) (fuse interruption characteristics in normal current mode (mechanical relay)). In this case, the protection function of the main line semiconductor fuse 531 is always enabled, and the interruption characteristics of the main line semiconductor fuse 531 are changed to either the interruption characteristics in the standby state or the interruption characteristics in the normal state depending on the power consumption state of the vehicle C. As a result, in the normal state, the fuse 521 (melt-type fuse) and mechanical relay 52, and the main line semiconductor fuse 531 are connected in parallel and have the same interruption characteristics, thereby achieving redundancy through a parallel circuit of the fuse 521 (melt-type fuse) and mechanical relay 52, and the main line semiconductor fuse 531. The interruption characteristics of the main line semiconductor fuse 531 in the standby state (fuse interruption characteristics in the low current consumption mode) are also set to be lower than the interruption characteristics of the branch line semiconductor fuse 532 in the normal state (interruption characteristics of the downstream semiconductor fuse).

[0046] 4 is a flowchart illustrating the processing of the control unit 11 of the in-vehicle device 1. The control unit 11 of the in-vehicle device 1 steadily performs the following processing when the vehicle C is stopped or started.

[0047] The control unit 11 of the in-vehicle device 1 acquires information on the power consumption state of the vehicle C (S101). The control unit 11 of the in-vehicle device 1, for example, acquires a signal from an IG switch or a power switch that controls the start and stop of the vehicle C, thereby grasping whether the vehicle C is in a started state or a stopped state. Alternatively, the control unit 11 of the in-vehicle device 1 may acquire, for example, information on the vehicle speed, information on the rotation of the engine or the driving motor, etc., from the in-vehicle ECU 2 connected to the in-vehicle network 3, thereby grasping whether the vehicle speed is 0 or not. The control unit 11 of the in-vehicle device 1 may derive (acquire) information on the power consumption state of the vehicle C depending on whether the vehicle C is in a running state (started state) or a parked state (stopped state). That is, the information on the power consumption state of the vehicle C includes information indicating whether the vehicle C is in a started state or a stopped state.

[0048] The power consumption state of the vehicle C includes a normal state (normal current mode) and a standby state (low current consumption mode) in which the power consumption is less than that of the normal state. The normal state includes, for example, a state in which the vehicle C is running (starting up) and indicates a state in which the power consumption of the vehicle C is equal to or greater than a predetermined value (normal current mode). The standby state includes, for example, a state in which the vehicle C is parked (stopped) and indicates a state in which the power consumption of the vehicle C is less than a predetermined value (low current consumption mode).

[0049] Alternatively, the normal state (normal current mode) may indicate a state in which the vehicle C is running or a parked state with an occupant on board, with the engine running and any on-board loads being driven. The standby state (low current consumption mode) may indicate a state in which the vehicle C is parked with no occupant on board, with the engine not running and any on-board loads not being driven. However, the on-board load may not be in a completely stopped state, but may be waiting to be immediately driven when, for example, a predetermined start signal is received. In other words, the standby state also includes a state in which such on-board loads or on-board ECU 2 are waiting to be immediately driven.

[0050] The storage unit 12 of the in-vehicle device 1 may store state definition information, which defines the correspondence between the power consumption state (normal state or standby state) and the state of the vehicle C or the in-vehicle load, for example in a table format (look-up table). The control unit 11 of the in-vehicle device 1 may derive (acquire) the power consumption state of the vehicle C by referring to the state definition information (look-up table). The control unit 11 of the in-vehicle device 1 derives information relating to the power consumption state of the vehicle C based on signals received from various switches or communication data such as messages received from the in-vehicle ECU 2 communicatively connected via the in-vehicle network 3, thereby acquiring the information.

[0051] The control unit 11 of the in-vehicle device 1 determines whether the vehicle C is in a standby state or not based on the information on the power consumption state of the vehicle C (S102). The control unit 11 of the in-vehicle device 1 determines whether the vehicle C is in a standby state (low current consumption mode) or in a normal state (normal current mode) based on the acquired information on the power consumption state of the vehicle C. The control unit 11 of the in-vehicle device 1 may store the determination result in the memory unit 12 in association with the time when the determination process was performed (determination time point).

[0052] When the vehicle C is in a standby state (S102: YES), the control unit 11 of the in-vehicle device 1 sets the main line semiconductor fuse 531 to interruption characteristics corresponding to the standby state, and activates the protection function (S103). When the vehicle C is in a standby state (low current consumption mode), the control unit 11 of the in-vehicle device 1 sets the main line semiconductor fuse 531 to interruption characteristics corresponding to the standby state. The interruption characteristics of the main line semiconductor fuse 531 corresponding to the standby state are shown as an interruption characteristic curve in a characteristics graph, for example, and are stored in the storage unit 12.

[0053] The control unit 11 of the in-vehicle device 1 may apply the interruption characteristic when executing an application or the like corresponding to the protection function of the main line semiconductor fuse 531, thereby enabling the protection function of the main line semiconductor fuse 531. Alternatively, in the case where the main line semiconductor fuse 531 is configured by, for example, an IPD (Intelligent Power Device), the control unit 11 may enable the protection function of the main line semiconductor fuse 531 by transmitting a signal to the IPD (main line semiconductor fuse 531) for starting (enabling) the protection function by applying the interruption characteristic according to the standby state.

[0054] The control unit 11 of the in-vehicle device 1 may further maintain (fix) the mechanical relay 52 in an open state (off) when the vehicle C is in a standby state (low current consumption mode). By maintaining (fixing) the mechanical relay 52 in an open state (off) when the vehicle C is in a standby state (low current consumption mode), it is possible to eliminate the need for opening and closing operations of the mechanical relay 52 in the standby state, thereby improving the durability (usable period, parts life) of the mechanical relay 52.

[0055] The control unit 11 of the in-vehicle device 1 disables the protection function of the branch line semiconductor fuse 532 (S104). The control unit 11 of the in-vehicle device 1 may disable the protection function of the branch line semiconductor fuse 532, for example, by stopping an application or the like corresponding to the protection function of the branch line semiconductor fuse 532. Alternatively, in the case where the branch line semiconductor fuse 532 is configured by, for example, an IPD (intelligent power device), the control unit 11 may disable the protection function of the branch line semiconductor fuse 532 by transmitting a signal for stopping (disabling) the protection function to the IPD (branch line semiconductor fuse 532).

[0056] In this way, it is possible to reduce the power consumption required to exert (execute) the protective function by disabling the protective function of the branch line semiconductor fuse 532. That is, the greater the number (three in this embodiment) of branch line semiconductor fuses 532 whose protective functions are disabled in the standby state (low current consumption mode), the greater the effect of reducing power consumption.

[0057] When enabling or disabling the respective protective functions of the main line semiconductor fuse 531 and the branch line semiconductor fuse 532, the control unit 11 of the in-vehicle device 1 enables the protective function of the main line semiconductor fuse 531 and then disables the protective function of the branch line semiconductor fuse 532. As a result, when the vehicle C transitions to a standby state, by first enabling the protective function of the main line semiconductor fuse 531, it is possible to reliably prevent the occurrence of a period during which both the protective functions of the main line semiconductor fuse 531 and the branch line semiconductor fuse 532 are disabled.

[0058] The control unit 11 of the in-vehicle device 1 starts the interruption control of the main line semiconductor fuse 531, whose interruption characteristics are set according to the standby state (S105). The interruption characteristics set in the main line semiconductor fuse 531 according to the standby state are lower than the smoke generation characteristics according to the multiple branch lines 512 and exceed the sum (combined value) of the current values ​​flowing through the multiple branch lines 512 when the vehicle C is in the standby state (interruption characteristics). If the current value (overcurrent) determined by the smoke generation characteristics according to the multiple branch lines 512 is set as the upper limit value and the sum (combined value) of the current values ​​flowing through the multiple branch lines 512 when the vehicle C is in the standby state is set as the lower limit value, the range of the current values ​​determined by these upper and lower limit values ​​is relatively wide. The interruption characteristics of the main line semiconductor fuse 531 in the standby state may be within the range of current values ​​determined by the upper and lower limit values, and therefore the degree of freedom in setting the interruption characteristics can be increased. As a result, when setting the interruption characteristics of the main line semiconductor fuse 531 in the standby state, the influence of the on-resistance of the main line semiconductor fuse 531 or errors in current value detection when performing interruption control can be reduced, resulting in a relatively robust control mode, and the safety of the in-vehicle system S can be efficiently ensured.

[0059] The control unit 11 of the in-vehicle device 1 acquires a current value of the current flowing in the main line 511 from a current detection unit 513 (main line current sensor) that is connected in series to the main line semiconductor fuse 531 and arranged in the main line 511. Alternatively, the control unit 11 may acquire a current value of the current flowing in the main line 511 from a main line current sensor built into the IPD that constitutes the main line semiconductor fuse 531. Based on an interruption characteristic curve (interruption characteristic according to a standby state) stored in the storage unit 12, when a current value corresponding to an overcurrent flows for a predetermined period or longer, the control unit 11 of the in-vehicle device 1 opens (turns off) the main line semiconductor fuse 531 to interrupt the current (overcurrent) flowing in the main line 511.

[0060] When the vehicle C is not in a standby state (S102: NO), that is, when the vehicle C is in a normal state, the control unit 11 of the in-vehicle device 1 activates the protection function of the branch line semiconductor fuse 532 (S1021). When the vehicle C is not in a standby state, that is, when the vehicle C is in a normal state (normal current mode), the control unit 11 of the in-vehicle device 1 may activate the protection function of the branch line semiconductor fuse 532 by executing an application or the like corresponding to the protection function of the branch line semiconductor fuse 532. Alternatively, when the branch line semiconductor fuse 532 is configured by, for example, an IPD (intelligent power device), the control unit 11 may activate the protection function of the branch line semiconductor fuse 532 by transmitting a signal to the IPD (branch line semiconductor fuse 532) for starting (activating) the protection function.

[0061] The control unit 11 of the in-vehicle device 1 disables the protection function of the main line semiconductor fuse 531 (S1022). The control unit 11 of the in-vehicle device 1 may disable the protection function of the main line semiconductor fuse 531 by stopping an application or the like corresponding to the protection function of the main line semiconductor fuse 531. Alternatively, when the main line semiconductor fuse 531 is configured by, for example, an IPD (Intelligent Power Device), the control unit 11 may disable the protection function of the main line semiconductor fuse 531 by transmitting a signal to the IPD (main line semiconductor fuse 531) for stopping (disabling) the protection function.

[0062] When enabling or disabling the respective protective functions of the main line semiconductor fuse 531 and the branch line semiconductor fuse 532, the control unit 11 of the in-vehicle device 1 enables the protective function of the branch line semiconductor fuse 532 and then disables the protective function of the main line semiconductor fuse 531. As a result, when the vehicle C transitions to the normal state, by first enabling the protective function of the branch line semiconductor fuse 532, it is possible to reliably prevent the occurrence of a period during which both the protective functions of the main line semiconductor fuse 531 and the branch line semiconductor fuse 532 are disabled.

[0063] Although the control unit 11 of the in-vehicle device 1 has been described as disabling the protection function of the main line semiconductor fuse 531 when the vehicle C is not in a standby state (in a normal state), this is not limiting. When the vehicle C is in a normal state, the control unit 11 of the in-vehicle device 1 may change (set) the cutoff characteristics of the main line semiconductor fuse 531 to cutoff characteristics corresponding to the normal state, i.e., the same cutoff characteristics as the mechanical relay 52 and the fuse 521 (melting type fuse). The main line semiconductor fuse 531, the mechanical relay 52, and the fuse 521 (melting type fuse) are connected in parallel (constitute a parallel circuit), and even if a fault occurs in either circuit, the other circuit can continue the protection function in the normal state of the vehicle C.

[0064] The control unit 11 of the in-vehicle device 1 starts the cutoff control for the branch line semiconductor fuse 532, the cutoff characteristics of which are set according to the normal state (S1023). The cutoff characteristics of each of the branch line semiconductor fuses 532 arranged on each of the multiple branch lines 512 are stored in the storage unit 12 as, for example, a cutoff characteristic curve. The control unit 11 of the in-vehicle device 1 starts the cutoff control for the branch line semiconductor fuse 532 according to the cutoff characteristic curve stored in the storage unit 12.

[0065] The control unit 11 of the in-vehicle device 1 acquires a current value of the branch line 512 from a branch line current sensor disposed on the branch line 512 or a current sensor built into the IPD constituting the branch line semiconductor fuse 532. When a current value corresponding to an overcurrent flows for a predetermined period or longer based on the interruption characteristic curve stored in the storage unit 12, the control unit 11 of the in-vehicle device 1 opens (turns off) the branch line semiconductor fuse 532 to interrupt the current (overcurrent) flowing through the branch line 512.

[0066] After executing step 105 or step S1023, the control unit 11 of the in-vehicle device 1 performs loop processing to perform the processing from step S101 again. This allows the control unit 11 of the in-vehicle device 1 to periodically or steadily continue the processing of acquiring (deriving) information on the power consumption state of the vehicle C, and to continuously perform the processing of determining whether the current state of the vehicle C is a standby state (low current consumption mode) or a normal state (normal current mode).

[0067] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope and meaning equivalent to the claims.

[0068] The claims may be combined with each other regardless of the form of reference. The claims may contain multiple dependent claims depending on multiple claims. Multiple dependent claims may be contained depending on multiple dependent claims. If multiple dependent claims are not contained depending on a multiple dependent claim, this does not limit the number of dependent claims depending on a multiple dependent claim. [Explanation of symbols]

[0069] C Vehicle S In-vehicle system 1 In-vehicle device 11 Control section 12 Storage section M Recording medium P Control program (program product) 13. Communications Department 14 Input / Output Interface 140 Signal Line 2 In-vehicle ECU 3. In-vehicle network 31 Communication Line 5 Power supply 51 Power line 511 Main line 512 Branch Line 513 Current detection unit (main line current sensor) 52 Mechanical Relay 521 Fuse (melting fuse) 531 Main Line Semiconductor Fuses 532 Branch line semiconductor fuse 6 On-vehicle load

Claims

1. An in-vehicle device that controls opening and closing of a plurality of semiconductor fuses provided in a power supply line from a power supply device mounted in a vehicle, a control unit that performs processing related to opening and closing control of the semiconductor fuse, the semiconductor fuses include a main line semiconductor fuse disposed on a main line, and branch line semiconductor fuses disposed on each of a plurality of branch lines branched from the main line, The control unit is Obtaining information regarding a power consumption state of the vehicle; According to the acquired information on the power consumption state of the vehicle, a protection function of the main line semiconductor fuse is enabled and a protection function of the branch line semiconductor fuse is disabled. In-vehicle device.

2. When enabling a protection function of the main line semiconductor fuse, the control unit sets an interruption characteristic of the main line semiconductor fuse so as to be lower than a smoke generation characteristic corresponding to the plurality of branch lines and to be higher than a sum of current values ​​flowing through the plurality of branch lines when the vehicle is in a standby state. The in-vehicle device according to claim 1 .

3. the power consumption state of the vehicle includes a normal state and a standby state in which power consumption is less than that of the normal state; The control unit is When the acquired information on the power consumption state of the vehicle indicates the standby state, a protection function of the main line semiconductor fuse is enabled and a protection function of the branch line semiconductor fuse is disabled; When the acquired information on the power consumption state of the vehicle indicates the normal state, the protection function of the main line semiconductor fuse is disabled and the protection function of the branch line semiconductor fuse is enabled. The vehicle-mounted device according to claim 2 .

4. a mechanical relay connected in parallel to the main line semiconductor fuse; The control unit maintains the mechanical relay in an open state when the vehicle is in a standby state. The vehicle-mounted device according to claim 2 .

5. The control unit is A current value flowing through the main line on which the main line semiconductor fuse is disposed is acquired; Based on the acquired current value, the main line semiconductor fuse having the interruption characteristic set according to the standby state is subjected to interruption control. The vehicle-mounted device according to claim 2 .

6. A program for causing a computer to execute processing for controlling opening and closing of a plurality of semiconductor fuses provided in a power supply line from a power supply device mounted on a vehicle, the semiconductor fuses include a main line semiconductor fuse disposed on a main line, and branch line semiconductor fuses disposed on each of a plurality of branch lines branched from the main line, Obtaining information regarding a power consumption state of the vehicle; According to the acquired information on the power consumption state of the vehicle, a protection function of the main line semiconductor fuse is enabled and a protection function of the branch line semiconductor fuse is disabled. A program that executes a process.

7. 1. An information processing method for causing a computer to execute processing for controlling opening and closing of a plurality of semiconductor fuses provided in a power supply line extending from a power supply device mounted on a vehicle, comprising: the semiconductor fuses include a main line semiconductor fuse disposed on a main line, and branch line semiconductor fuses disposed on each of a plurality of branch lines branched from the main line, Obtaining information regarding a power consumption state of the vehicle; According to the acquired information on the power consumption state of the vehicle, a protection function of the main line semiconductor fuse is enabled and a protection function of the branch line semiconductor fuse is disabled. An information processing method for executing a process.

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