In-vehicle device

Abstract

The in-vehicle device according to an embodiment of the present disclosure comprises: a conductive pattern on which switching devices are placed that are provided on a power line from a power supply device mounted on a vehicle; and a control unit that applies voltages to the switching devices via the conductive pattern and thereby controls an output of power to the downstream side in the flow direction of the current from the power supply device of each switching device. The conductive pattern is formed corresponding to the switching devices of different types. The control unit differentiates control to be performed on the switching devices in accordance with the types of the switching devices placed on the conductive pattern.

Description

In-vehicle device

[0001] This application claims priority to Japanese Patent Application No. 2023-210515, filed December 13, 2023, and incorporates by reference all of the contents of that application.

[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 semiconductor switch 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 semiconductor switch on or off.

[0003] A semiconductor switch has a control end. For example, if the semiconductor switch is a FET (Field Effect Transistor), the control end is a gate. The resistance value across the semiconductor switch varies depending on the voltage at the control end. By adjusting the voltage at the control end, the resistance value across the semiconductor switch is adjusted to a sufficiently small value, and the semiconductor switch is turned on. By adjusting the voltage at the control end, the resistance value across the semiconductor switch is adjusted to a sufficiently large value, and the semiconductor switch is turned off.

[0004] JP 2013-143905 A

[0005] An on-board device according to one embodiment of the present disclosure includes a conductive pattern on which opening / closing devices are placed, the opening / closing devices being provided on a power line from a power supply device mounted on a vehicle, and a control unit that controls the output of power from each opening / closing device to the downstream side in the direction of current flow from the power supply device by applying a voltage to the opening / closing device via the conductive pattern, the conductive pattern being formed to correspond to different types of opening / closing devices, and the control unit differs in the control it performs on the opening / closing devices depending on the type of opening / closing device placed on the conductive pattern.

[0006] Fig. 1 is a block diagram showing an example of connection between a microcomputer and a shut-off IPD in an in-vehicle device; Fig. 2 is a block diagram showing an example of connection between a microcomputer and a non-shut-off IPD in an in-vehicle device; Fig. 3 is a flowchart showing an example of a mounted IPD determination process; Fig. 4 is a flowchart showing an example of a control selection process; Fig. 5 is a block diagram showing an example of connection between a microcomputer and an IPD in an in-vehicle device according to a second embodiment; Fig. 6 is a flowchart showing an example of a mounted IPD determination process according to a second embodiment;

[0007] [Problem to be Solved by the Present Disclosure] However, the power supply control device of Document 1 does not take into consideration compatibility with different types of switching devices.

[0008] The present disclosure has been made in view of the above circumstances, and has an object to provide an in-vehicle device that can be adapted to different types of opening and closing devices.

[0009] Effect of the Present Disclosure In an in-vehicle device according to an embodiment of the present disclosure, it is possible to mount a plurality of types of opening and closing devices on a common conductive pattern.

[0010] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. In addition, at least some of the embodiments described below may be combined in any manner.

[0011] (1) An in-vehicle device according to one aspect of the present disclosure includes a conductive pattern on which opening / closing devices are placed, the opening / closing devices being provided on a power line from a power supply device mounted on a vehicle, and a control unit that controls the output of power from each opening / closing device to the downstream side in the direction of current flow from the power supply device by applying a voltage to the opening / closing device via the conductive pattern, the conductive pattern being formed to correspond to different types of opening / closing devices, and the control unit differs in the control it performs on the opening / closing devices depending on the type of opening / closing device placed on the conductive pattern.

[0012] In this aspect, the switching device is, for example, an IPD (Intelligent Power Device). The switching device is mounted on a conductive pattern provided on a substrate included in the in-vehicle device. The conductive pattern is composed of a plurality of lands, and the switching device is mounted on the conductive pattern on the substrate by connecting a plurality of pin terminals provided on the switching device to the lands. The switching device outputs power supplied from a power supply device via a power line to a downstream load. The switching device is connected to a control unit via a control line, and the control unit controls the power output to the downstream load of the switching device by applying a voltage to the switching device. The type of switching device mounted on the conductive pattern is changed depending on the downstream load. For example, if the load does not need to be controlled by PWM (Pulse Width Modulation), an inexpensive switching device is mounted on the conductive pattern. The switching device does not have a temperature calculation function (temperature estimation function, current interruption function) that calculates the temperature of the power line and interrupts the current flowing through the power line when the calculated temperature exceeds a threshold (interruption threshold). If the load requires PWM control, a switchgear having a temperature calculation function is mounted on the conductive pattern. The switchgear outputs power corresponding to a PWM signal from a control unit to a downstream load and cuts off the current when an overcurrent occurs. When a switchgear without a temperature calculation function is mounted on the conductive pattern, the control unit acquires a current value of the power output from the switchgear to the downstream side and performs control (cutoff control) to cut off (stop) the switchgear's power output to the downstream side based on the acquired current value (an integrated value based on at least one of the current value, the electrical resistance value of the power line, and the time constant of the power line). The control unit may also calculate (estimate) the temperature of the power line based on the acquired current value and perform cutoff control based on the calculated temperature. When a switchgear with a temperature calculation function is mounted on the conductive pattern, the control unit does not perform cutoff control. By varying the control performed by the control unit depending on the switchgear mounted on the conductive pattern, it is possible to mount multiple types of switchgears on a common conductive pattern. This is expected to enable component standardization and reduce product costs.Furthermore, when a load that needs to be controlled by PWM is connected, it is possible to place a switching device with a temperature calculation function on the conductive pattern, so that the control unit does not need to perform shut-off control, and the processing load on the control unit can be reduced.

[0013] (2) In an in-vehicle device according to one aspect of the present disclosure, the conductive pattern includes a common portion that is used in common when different types of opening and closing devices are installed, and a non-common portion that is used only when one of the different types of opening and closing devices is installed.

[0014] In this aspect, the switchgear includes multiple terminals (pin terminals, PIN). For example, a switchgear with a temperature calculation function (interrupter switchgear) and a switchgear without a temperature calculation function (non-interrupter switchgear) have the same number of terminals, so it is possible to mount either the interrupter switchgear or the non-interrupter switchgear on a common conductive pattern. The terminals of the interrupter switchgear and the non-interrupter switchgear correspond to each other except for some terminals and have common functions. Note that these terminals (non-common terminals) of the interrupter switchgear include, for example, a terminal that outputs the state of the own switching device to the control unit, a terminal that accepts input of an interruption characteristic related to the temperature calculation function, or a terminal that accepts input of an interruption threshold related to the temperature calculation function. Furthermore, the non-common terminal is connected to the non-common part, and when the non-common terminal of the interrupter switchgear is connected, for example, a resistor component is provided in the non-common part. By changing the resistor component provided in the non-common part, the interruption characteristic or the interruption threshold input to the interrupter switchgear can be changed. The part of the terminals (non-common terminals) of the non-interrupting switchgears is, for example, a non-connection (NC) terminal, and when the non-common terminals of the non-interrupting switchgears are connected to the non-common section, no resistive component is provided in the non-common section. That is, the non-common terminals of the non-interrupting switchgears may be provided as dummy terminals that do not input or output signals. By providing common and non-common sections in the conductive pattern and enabling both an interrupting switchgear and a non-interrupting switchgear to be mounted, the conductive pattern used can be made common depending on the load.

[0015] (3) In an in-vehicle device according to one aspect of the present disclosure, the type of the opening / closing device is classified according to whether or not it has a temperature calculation function, and when the opening / closing device placed on the conductive pattern does not have a temperature calculation function, the control unit acquires the current value of the power output by the opening / closing device and performs cut-off control to cut off the output of power to the downstream side of the opening / closing device based on at least one of the acquired current value, the electrical resistance value of the power line, and the time constant of the power line, and when the opening / closing device has a temperature calculation function, performs opening / closing control to control the output of power to a load connected to the opening / closing device without performing cut-off control based on the current value flowing through the opening / closing device.

[0016] In this aspect, the switching device (IPD) having a temperature calculation function cuts off the output of power downstream when, for example, an integrated value of the output current value over a predetermined time period exceeds a threshold value based on at least one of the current value of the power output from the switching device in response to the PWM signal output by the control unit, the electrical resistance value of the power line, and the time constant of the power line. The switching device (IPD) having a temperature calculation function may also cut off the output of power downstream based on the duty ratio of the PWM signal output by the control unit. In contrast, an inexpensive switching device (IPD) does not have a temperature calculation function. When an inexpensive switching device without a temperature calculation function is mounted on a conductive pattern, the control unit detects an overcurrent flowing in the power line based on the current value acquired from the switching device and cuts off the output of power downstream from the switching device. This makes it possible to cut off the output of power downstream from the switching device and protect the load when an overcurrent flows in the power line, even when the switching device mounted on the conductive pattern does not have a temperature calculation function. Furthermore, when a switching device having a temperature calculation function is mounted on the conductive pattern, the control unit does not execute the cutoff control, and the processing load of the control unit can be reduced. Note that the control unit may calculate (estimate) the temperature of the power line and execute the cutoff control based on the calculated temperature.

[0017] (4) In one aspect of the in-vehicle device of the present disclosure, the opening / closing device has a plurality of terminals, and the control unit acquires a signal output from a specific terminal among the plurality of terminals of the opening / closing device, and determines whether the opening / closing device has a temperature calculation function based on the acquired signal.

[0018] In this aspect, a switchgear having a temperature calculation function is switched to an idle mode in which the current consumption of the own switching device is also reduced, for example, when the current value of the output power is small. The switchgear having a temperature calculation function outputs a signal indicating whether the own switching device is in the idle mode to the control unit from a specific terminal among the multiple terminals provided in the switchgear. In contrast, in a switchgear without a temperature calculation function, the terminal corresponding to the specific terminal (the terminal connected to the same land on the conductive pattern as the specific terminal of the switchgear having the temperature calculation function) is an NC (non-connection) terminal, and no signal is output from the terminal to the control unit. When the control unit receives a signal from the specific terminal of the switchgear, it determines that the switchgear placed on the conductive pattern has the temperature calculation function. When the control unit does not receive a signal, it determines that the switchgear placed on the conductive pattern does not have the temperature calculation function. This allows the control unit to execute control corresponding to the switchgear placed on the conductive pattern.

[0019] (5) In an in-vehicle device according to one aspect of the present disclosure, the control unit transmits a signal to the opening / closing device requesting information about the type of the opening / closing device placed on the conductive pattern, obtains a response signal from the opening / closing device in response to the transmitted signal, and determines whether the opening / closing device has a temperature calculation function based on the response signal.

[0020] In this aspect, the control unit and the switching device can communicate with each other via serial communication such as SPI (Serial Peripheral Interface) communication. The control unit transmits a signal requesting information about the type of switching device to the switching device placed on the conductive pattern. The switching device that receives the signal requesting information about the type of switching device from the control unit transmits information indicating its own switching device type to the control unit as a response signal. The control unit determines whether the switching device placed on the conductive pattern has a breaking function based on the response signal. This allows the control unit to execute control corresponding to the switching device placed on the conductive pattern.

[0021] (6) In an in-vehicle device according to one aspect of the present disclosure, when the load connected to the switching device is a load that corresponds to PWM control, the switching device having a temperature calculation function is mounted on the conductive pattern, and when the load connected to the switching device is a load that does not correspond to PWM control, the switching device without a temperature calculation function is mounted on the conductive pattern.

[0022] In this embodiment, a load (on-board load) is connected to a switching device mounted on the conductive pattern 33. That is, if the load connected to the switching device is a load that needs to be controlled by PWM (compatible with PWM control), such as an illumination lamp whose brightness changes, a switching device with a temperature calculation function is mounted on the conductive pattern. If the load connected to the switching device is a load that does not need to be controlled by PWM (not compatible with PWM control), such as a headlight or interior light whose brightness does not change, an inexpensive switching device without a temperature calculation function is mounted on the conductive pattern. By changing the type of switching device mounted on the conductive pattern depending on whether the load connected to the switching device needs to be controlled by PWM, it is possible to reduce the manufacturing cost of the on-board device. Furthermore, if a load that needs to be controlled by PWM is connected, a switching device with a temperature calculation function can be mounted on the conductive pattern, so the control unit does not need to perform shut-off control, and the processing load of the control unit can be reduced.

[0023] [Details of the embodiment of the present disclosure] Specific examples of a power supply control device 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 defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0024] (Embodiment 1) FIG. 1 is a block diagram showing an example of a connection between a microcomputer 31 and a shutoff IPD 32a in an in-vehicle device 3. FIG. 2 is a block diagram showing an example of a connection between a microcomputer 31 and a non-shutoff IPD 32b in an in-vehicle device 3. The in-vehicle device 3 is, for example, an individual ECU (Electronic Control Unit) mounted on a vehicle M. The in-vehicle device 3 may be a left-zone ECU mounted in the left zone of the vehicle M or a right-zone ECU mounted in the right zone. The in-vehicle device 3 is connected to a positive electrode of a power supply device 1 and one end of a load 4. The negative electrode of the power supply device 1 and the other end of the load 4 are grounded. In the following description, in the current path from the power supply device 1 to the load 4, the power supply device 1 side is referred to as the upstream side of the current, and the load 4 side is referred to as the downstream side of the current. In FIGS. 1 and 2, and FIG. 5 described later, power lines are indicated by thick solid lines, and control lines are indicated by thin solid lines.

[0025] The in-vehicle device 3 includes a microcomputer (MCU) 31, an IPD (Intelligent Power Device) 32, and a conductive pattern 33 on which the IPD 32 is mounted. The IPD 32 corresponds to a switching device. Note that FIG. 1 shows an example in which a shutoff IPD 32a having a temperature calculation function is mounted on the conductive pattern 33. The IPD 32 receives power supplied from the power supply device 1 and controls the power output to the load 4 based on the state of the voltage applied from the MCU 31. Specifically, the IPD 32 includes, for example, an N-channel field effect transistor (FET). The drain of the FET is connected to the power supply device 1, and the source is connected to the load 4. The gate of the FET is connected to the MCU 31, and the voltage applied to the IPD 32 is applied to the gate of the FET. As a result, when a high-level voltage is applied to the IPD 32, the IPD 32 outputs power to the downstream load 4. Furthermore, when a low-level voltage is applied to the IPD 32, the IPD 32 does not output power to the downstream load 4. The switching device (IPD 32) may be configured by a P-channel FET, a mechanical relay, or the like.

[0026] The microcomputer 31 has a control unit 311, a storage unit 312, and an input / output I / F 313. These are connected to an internal bus 315. Furthermore, the microcomputer 31 may have an in-vehicle communication unit (not shown) using a CAN or the like, and may be connected to an in-vehicle ECU or the like so as to be able to communicate with the in-vehicle ECU via an in-vehicle network.

[0027] The control unit 311 has a processing element, such as a CPU (Central Processing Unit), that executes processing and functions as a processing unit. The processing element of the control unit 311 reads and executes a computer program (program) P stored in the storage unit 312 to execute processing for controlling the output of power to the downstream side of each IPD 32, processing for determining whether the placed IPD 32 has a temperature calculation function, and processing for stopping the output of power to the downstream side of each IPD 32 when an overcurrent flows through each IPD 32. Note that the processing executed by the control unit 311 may be executed by an external device connected to the in-vehicle device 3 wirelessly or via a wire.

[0028] The storage unit 312 is a non-volatile memory. A computer program P is stored in the storage unit 312. The computer program P may be provided to the microcomputer 31 using a non-transitory storage medium A on which the computer program P is readably recorded. The storage medium A is, for example, a portable memory. If the storage medium A is a portable memory, the processing element of the control unit 311 may read the computer program P from the storage medium A using a reading device (not shown). The read computer program P is stored in the storage unit 312. Furthermore, the computer program P may be provided to the microcomputer 31 by an in-vehicle communication unit (not shown) of the microcomputer 31 communicating with an external device. The storage unit 312 also stores determination results or thresholds, which will be described later. The thresholds stored in the storage unit 312 may be changed by reprogramming, for example, depending on the load 4 connected to the in-vehicle device 3 or the type of IPD 32 provided in the in-vehicle device 3. The thresholds stored in the storage unit 312 may also be updated through communication with an external device.

[0029] The input / output I / F 313 includes a plurality of pin terminals (PIN(a), PIN(b), PIN(c), ...). Each pin terminal of the microcomputer 31 is connected to each pin terminal of the IPD 32 via a control line and a conductive pattern 33.

[0030] The IPD 32 includes a power receiving terminal 321 and a power output terminal 322. A power line connecting the power supply device 1 and the IPD 32 of the in-vehicle device 3 is connected to the power receiving terminal 321, and the power receiving terminal 321 receives power supplied from the upstream side. A power line connecting the IPD 32 and the load 4 is connected to the power output terminal 322, and the power received by the power receiving terminal 321 is output to the downstream load 4.

[0031] The IPD 32 includes a plurality of pin terminals (PIN(1), PIN(2), PIN(3), ...). The conductive pattern 33 includes a plurality of lands L (L1, L2, L3, ...). The PIN(1) of the IPD 32 is grounded via the land L1.

[0032] PIN (2) of the IPD 32 is connected to PIN (a) of the microcomputer 31 via land L2. A resistive component R1 for preventing overvoltage or overcurrent is provided on land L2. The control unit 311 of the microcomputer 31 applies a voltage from PIN (a) to PIN (2) of the IPD 32 to control the power output of the IPD 32. When a high-level voltage is applied to PIN (2), the IPD 32 outputs power downstream. When a low-level voltage is applied to PIN (2), the IPD 32 does not output power downstream.

[0033] PIN (3) of the IPD 32 is connected to PIN (b) of the microcomputer 31 via land L3. A resistive component R2 for preventing overvoltage or overcurrent is provided on land L3. The control unit 311 of the microcomputer 31 applies a voltage from PIN (b) to PIN (3) of the IPD 32 to switch whether or not to output to the microcomputer 31 a current value corresponding to the power output by the IPD 32 downstream. PIN (4) of the IPD 32 is connected to PIN (c) of the microcomputer 31 via land L4. When a high-level voltage is applied to PIN (3), the IPD 32 outputs a current value corresponding to the power output by the IPD 32 downstream from PIN (4) to PIN (c) of the microcomputer 31. A pull-down resistor component Rd is provided on land L4, and the current value output from the IPD 32 to the microcomputer 31 via PIN (4) is converted into a voltage value corresponding to (proportional to) the current value and input to PIN (c) of the microcomputer 31. That is, the control unit 311 transmits a signal to PIN (3) of the IPD 32 to instruct it to output a current value. Upon receiving the signal to instruct it to output a current value, the IPD 32 outputs, from PIN (4), a current value corresponding to the power that the IPD 32 outputs downstream.

[0034] The PIN (5) of the IPD 32 is grounded via the land L5. As shown in FIG. 1 , when the shutoff IPD 32a is mounted on the conductive pattern 33, a resistor R3 is provided on the land L5. The shutoff IPD 32a has a temperature calculation function that stops power output to the load 4 connected downstream when an overcurrent flows through the shutoff IPD 32a. A voltage is applied to the PIN (5) of the shutoff IPD 32a to determine the shutoff characteristics (time until shutoff relative to the current value of the overcurrent) related to the temperature calculation function. The voltage value applied to the PIN (5) is based on the resistance value of the resistor R3 provided on the PIN (5). In other words, the shutoff characteristics of the shutoff IPD 32a are determined based on the resistance value of the resistor R3 provided on the PIN (5).

[0035] 2, when the non-interrupting IPD 32b is mounted on the conductive pattern 33, R3 is not provided on the land L5, and the PIN (5) of the non-interrupting IPD 32b is not electrically connected to any location. That is, the PIN (5) of the non-interrupting IPD 32b is an NC (Non Connection) terminal, and is only structurally connected to the land L5, and input / output to the non-interrupting IPD 32b via the land L5 is not performed, and the land L5 is not used.

[0036] PIN (6) of the IPD 32 is connected to PIN (d) of the microcomputer 31 via land L6. As shown in FIG. 1 , when the shutoff IPD 32a is mounted on the conductive pattern 33, a pull-up resistor Ru is provided on land L6 and connected to the Vcc power supply. The shutoff IPD 32a transmits a signal indicating the state (mode) of the shutoff IPD 32a to PIN (d) of the microcomputer 31 using a voltage applied from the Vcc power supply. The states of the shutoff IPD 32a include a normal mode in which the shutoff IPD 32a outputs a high current and consumes a high current, and a low-consumption mode (idle mode) in which the shutoff IPD 32a outputs a lower current and consumes a lower current than in the normal mode. When the shutoff IPD 32a is in the normal mode, it applies a low-level voltage to PIN (d) of the microcomputer 31 to transmit a signal indicating that the shutoff IPD 32a is not in the idle mode. When the shutdown IPD 32a is in the idle mode, the shutdown IPD 32a applies a high-level voltage to the PIN (d) of the microcomputer 31, thereby transmitting a signal indicating that the shutdown IPD 32a is in the idle mode.

[0037] 2, when a non-interrupting IPD 32b is mounted on the conductive pattern 33, Ru is not provided on the land L6, and no voltage is applied to the PIN(d). That is, the PIN(d) of the microcomputer 31 does not receive a signal from the IPD 32, and the land L6 is not used. The control unit 311 of the microcomputer 31 can determine whether the IPD 32 mounted on the conductive pattern 33 is the interrupting IPD 32a or the non-interrupting IPD 32b based on the voltage applied to the PIN(d) (the signal acquired by the PIN(d)).

[0038] The PIN (7) of the IPD 32 is grounded via the land L7. As shown in FIG. 1 , when the shutoff IPD 32a is mounted on the conductive pattern 33, a resistive component R4 is provided on the land L7. The shutoff IPD 32a has a temperature calculation function that stops power output to the load 4 connected downstream when an overcurrent flows through the shutoff IPD 32a. A voltage that determines the temperature shutoff threshold related to the temperature calculation function is applied to the PIN (7) of the shutoff IPD 32a. The voltage value applied to the PIN (7) is based on the resistance value of the resistive component R4 provided on the PIN (7). In other words, the shutoff threshold of the shutoff IPD 32a is determined based on the resistance value of the resistive component R4 provided on the PIN (7). The shutoff threshold may be a threshold value of the integrated current value of the overcurrent that shuts off the current.

[0039] 2, when the non-interrupting IPD 32b is mounted on the conductive pattern 33, R4 is not provided on the land L7, and the PIN (7) of the non-interrupting IPD 32b is not electrically connected to any location. In other words, the PIN (7) of the non-interrupting IPD 32b is an NC (Non Connection) terminal, and is only structurally connected to the land L7, and input / output to the non-interrupting IPD 32b via the land L7 is not performed, and the land L7 is not used.

[0040] As described above, the lands L1, L2, L3, and L4 are used regardless of whether the shutoff IPD 32a or the non-shutoff IPD 32b is mounted on the conductive pattern 33. The lands L1, L2, L3, and L4 form a common portion 33a of the conductive pattern 33. The lands L5, L6, and L7 are used when the shutoff IPD 32a is mounted on the conductive pattern 33, but are not used when the non-shutoff IPD 32b is mounted on the conductive pattern 33. The lands L5, L6, and L7 form a non-common portion 33b of the conductive pattern 33.

[0041] The load 4a shown in FIG. 1 is a load that needs to be controlled by PWM, such as an illumination lamp whose brightness changes. When the load 4a mounted on the vehicle M and connected to the IPD 32 of the on-board device 3 needs to be controlled by PWM, a shutoff IPD 32a is mounted on the conductive pattern 33 as shown in FIG. 1 . As described above, the shutoff IPD 32a has a temperature calculation function. When the shutoff IPD 32a is mounted on the conductive pattern 33, the control unit 311 of the microcomputer 31 applies a voltage from PIN(a) to the shutoff IPD 32a using a PWM signal to control the output of power downstream of the shutoff IPD 32a. If an overcurrent flows through the shutoff IPD 32a, the shutoff IPD 32a stops outputting power. Therefore, the control unit 311 of the microcomputer 31 does not execute control to determine whether an overcurrent is flowing through the shutoff IPD 32a based on a current value corresponding to the power output downstream from the shutoff IPD 32a.

[0042] The load 4b shown in FIG. 2 is a load that does not require PWM control, such as a headlight or interior light whose brightness does not change. When the load 4b mounted on the vehicle M and connected to the IPD 32 of the on-board device 3 is a load 4b that does not require PWM control, a non-interrupting IPD 32b is mounted on the conductive pattern 33 as shown in FIG. 2. As described above, the non-interrupting IPD 32b does not have a temperature calculation function. When the non-interrupting IPD 32b is mounted on the conductive pattern 33, the control unit 311 of the microcomputer 31 controls the voltage applied from PIN(a) to the non-interrupting IPD 32b and controls the output of power downstream of the non-interrupting IPD 32b. The control unit 311 of the microcomputer 31 also executes control to determine whether an overcurrent is flowing through the non-interrupting IPD 32b based on at least one of a current value corresponding to the power output downstream by the non-interrupting IPD 32b, the electrical resistance value of the power line, and the time constant of the power line. If the control unit 311 determines that an overcurrent is flowing through the non-interrupting IPD 32b, it stops the output of power to the downstream side of the non-interrupting IPD 32b by applying a low-level voltage from PIN (a) to PIN (2) of the non-interrupting IPD 32b.

[0043] As described above, the tripping IPD 32a functions as a semiconductor fuse that independently detects an overcurrent and stops the output of power. In contrast, the non-tripping IPD 32b stops the output of power under the control of the microcomputer 31 when the microcomputer 31 detects an overcurrent. In other words, the non-tripping IPD 32b and the microcomputer 31 function together as a semiconductor fuse.

[0044] 3 is a flowchart illustrating an example of the process for determining whether an IPD is placed. The control unit 311 of the microcomputer 31 determines whether a signal indicating the state of the IPD 32 is being output from the PIN (6) of the IPD 32 (S1). If a signal indicating the state of the IPD 32 is being output from the PIN (6) of the IPD 32 (S1: YES), the control unit 311 determines that a blocked IPD 32a is being placed on the conductive pattern 33 (S2). If a signal indicating the state of the IPD 32 is not being output from the PIN (6) of the IPD 32 (S1: NO), the control unit 311 determines that a non-blocking IPD 32b is being placed on the conductive pattern 33 (S3). The control unit 311 stores the results of the determinations made in S2 or S3 in the storage unit 312 (S4) and terminates the process. In S4, the control unit 311 stores the results of the determination in the storage unit 312, for example, by storing a numerical flag corresponding to the type of IPD 32 determined to be placed in the storage unit 312. 3 during the manufacturing stage of the vehicle M. The control unit 311 may also execute the on-board IPD determination process when the vehicle M is undergoing maintenance, is stopped, or is being charged.

[0045] 4 is a flowchart showing an example of the control selection process. The control unit 311 of the microcomputer 31 reads the determination result stored in the memory unit 312 (S11). Based on the read determination result, the control unit 311 determines whether the shutoff IPD 32a is placed on the conductive pattern 33 (whether the non-shutoff IPD 32b is placed) (S12). If the shutoff IPD 32a is placed (S12: YES), the control unit 311 starts outputting a PWM signal from PIN(a) to the IPD 32 (S13) and ends the process. That is, in S13, the control unit 311 executes control corresponding to the load 4 (load 4a) that requires PWM control.

[0046] If the shutoff IPD 32a is not installed (if the non-shutoff IPD 32b is installed) (S12: NO), the control unit 311 transmits a signal from PIN(b) to PIN(3) of the IPD 32 instructing the IPD 32 to output a current value corresponding to the power to be output downstream (S14). The IPD 32 (non-shutoff IPD 32b) that receives the signal instructing the IPD 32 to output a current value corresponding to the power to be output downstream (proportional to the current value of the power) outputs to the microcomputer 31. The control unit 311 acquires the current value output by the IPD 32 (S15). Based on the acquired current value, the control unit 311 determines whether an overcurrent is flowing through the IPD 32, and if an overcurrent is flowing, initiates shutoff control to stop the IPD 32 from outputting power downstream (S16). The control unit 311 also initiates application of a voltage to control the power output downstream of the IPD 32 (S17), and ends the process. That is, the control unit 311 executes control corresponding to the load 4 (load 4b) that does not require PWM control in steps S14 to S17. Note that the control unit 311 may execute the shut-off control of the IPD 32b and the application of voltage to the IPD 32b in parallel.

[0047] The control unit 311 of the microcomputer 31 executes the control selection process shown in Fig. 4 when the vehicle M is started, for example. The control unit 311 may execute a process similar to the on-board IPD determination process shown in Fig. 3 when the vehicle M is started. At this time, if the determination result at the start of the vehicle M differs from the determination result stored in the storage unit 312, the control unit 311 may issue an alarm to the outside via, for example, the in-vehicle communication unit. Furthermore, if the determination result at the start of the vehicle M differs from the determination result stored in the storage unit 312, the vehicle M may be stopped, or the control by the in-vehicle device 3 for which the determination result differs may be stopped, and the vehicle M may be started in a state in which the operation of some functions is stopped or limited.

[0048] (Embodiment 2) The microcomputer 31 and the IPD 32 of the in-vehicle device 3 according to the second embodiment communicate with each other via serial communication such as SPI (Serial Peripheral Interface) communication. FIG. 5 is a block diagram illustrating an example of a connection between the microcomputer 31 and the IPD 32 in the in-vehicle device 3 according to the second embodiment. Note that FIG. 5 illustrates an example in which a shutoff IPD 32a is mounted on the conductive pattern 33. The microcomputer 31 and the IPD 32 according to the second embodiment are connected via a communication line. In FIG. 5, the communication line is indicated by a dashed line. The microcomputer 31 transmits a signal via the communication line to the IPD 32 requesting information on the type of the IPD 32 (whether or not it has a shutoff function). The IPD 32, having received the signal via the communication line, transmits information indicating the type of its own IPD 32 as a response signal via the communication line to the microcomputer 31. Based on the response signal from the IPD 32, the microcomputer 31 can determine whether the IPD 32 mounted on the conductive pattern 33 is a shutoff IPD 32a or a non-shutoff IPD 32b. The microcomputer 31 may control the IPD 32 by SPI communication via a communication line. The microcomputer 31 and the IPD 32 may communicate with each other by parallel communication.

[0049] 6 is a flowchart showing an example of a mounted IPD determination process according to the second embodiment. The control unit 311 of the microcomputer 31 transmits a signal (request signal) requesting information about the type of the IPD 32 to the IPD 32 (S21). The IPD 32, having received the request signal, transmits information indicating the type of its own IPD 32 as a response signal, and the control unit 311 receives the response signal (S22). The control unit 311 determines the type of the IPD 32 mounted on the conductive pattern 33 (shutoff IPD 32a or non-shutoff IPD 32b) based on the received response signal (S23). The control unit 311 stores the determined type of the IPD 32 in the storage unit 312 (S24), and the process ends.

[0050] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The technical features described in each embodiment may be combined with one another, and the scope of the present invention is intended to include all modifications within the scope of the claims and equivalents thereto. Furthermore, independent and dependent claims described in the claims may be combined with one another in any and all combinations, regardless of the reference format. Furthermore, while the claims use a format in which a claim references two or more other claims (multiple claim format), this is not limiting. Multiple claims (multiple multiple claims) that reference at least one other claim may also be used.

[0051] REFERENCE SIGNS LIST 1 Power supply device 3 On-board device 31 Microcomputer (microcomputer) 311 Control unit 312 Storage unit 313 Input / output I / F 32 IPD 32a Shut-off IPD 32b Non-shut-off IPD 33 Conductive pattern 33a Common unit 33b Non-common unit 4 Load A Storage medium M Vehicle P Computer program (program)

Claims

1. An on-vehicle device comprising: a conductive pattern on which switching devices are placed, the switching devices being provided on a power line from a power supply device mounted on a vehicle; and a control unit which controls the output of power from each of the switching devices to the downstream side in the direction of current flow from the power supply device by applying a voltage to the switching devices via the conductive pattern, the conductive pattern being formed corresponding to different types of switching devices, and the control unit differs in the control it performs on the switching devices depending on the type of the switching device placed on the conductive pattern.

2. The in-vehicle device according to claim 1, wherein the conductive pattern comprises: a common portion that is used in common when different types of opening / closing devices are installed; and a non-common portion that is used only when any one of the different types of opening / closing devices is installed.

3. The in-vehicle device according to claim 1 or 2, wherein the types of the switching device are classified according to whether or not they have a temperature calculation function, and wherein the control unit, when the switching device placed on the conductive pattern does not have a temperature calculation function, acquires a current value of the power output by the switching device, and executes cut-off control to cut off the output of power to the downstream side of the switching device based on at least one of the acquired current value, the electrical resistance value of the power line, and the time constant of the power line, and when the switching device has a temperature calculation function, executes opening and closing control to control the output of power to a load connected to the switching device without executing cut-off control based on the value of the current flowing through the switching device.

4. An in-vehicle device as described in claim 1 or 2, wherein the opening / closing device has a plurality of terminals, and the control unit acquires a signal output from a specific terminal among the plurality of terminals of the opening / closing device, and determines whether or not the opening / closing device has a temperature calculation function based on the acquired signal.

5. The in-vehicle device according to claim 1 or 2, wherein the control unit transmits to the opening / closing device a signal requesting information on the type of the opening / closing device placed on the conductive pattern, acquires a response signal from the opening / closing device in response to the transmitted signal, and determines whether or not the opening / closing device has a temperature calculation function based on the response signal.

6. An in-vehicle device as described in claim 1 or 2, wherein the conductive pattern is mounted with the switching device having a temperature calculation function when the load connected to the switching device is a load that supports PWM control, and is mounted with the switching device without the temperature calculation function when the load connected to the switching device is a load that does not support PWM control.

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