Power supply control device, power supply control method, and computer program

Abstract

To provide a power supply control device, a power supply control method, and a computer program capable of correctly estimating an electric wire temperature for a plurality of types of loads having different driving current values.SOLUTION: A power supply control device for a vehicle that controls power supply to a load based on a temperature estimation result of an electric wire connected to the load, the power supply control device comprising: a changing unit that changes a parameter for the temperature estimation in accordance with the load; and an estimation unit that performs the temperature estimation using the changed parameter.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a power supply control device, a power supply control method, and a computer program. [Background technology]

[0002] Conventionally, there has been widespread technology for preventing smoke from being emitted from an electric wire when the temperature of the electric wire rises due to a short circuit current caused by repeated on / off switching in a vehicle.

[0003] For example, Patent Document 1 discloses a power supply control device that detects the current in an electric wire when it is energized, uses that current to estimate the current temperature of the electric wire, and compares the current temperature with the upper limit temperature allowed for the electric wire, thereby cutting off the current before the electric wire reaches the smoking temperature, thereby preventing the electric wire from smoking. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-130944 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the current value used for driving the load differs depending on the load, the power supply cable connected to the load must also be changed depending on the load. Furthermore, since the parameters used to estimate the above-mentioned power supply temperature also differ depending on the cable, it is necessary to prepare a power supply control device with different parameters for each load in advance. In other words, the number of product types for power supply control devices increases, leading to an increase in manufacturing costs.

[0006] Furthermore, if the load is changed or added after the vehicle is shipped and the connected electric wires are replaced, the parameters used to estimate the electric wire temperature remain the same as when the vehicle was shipped, even though the electric wires have been replaced, which poses a problem that the electric wire temperature cannot be estimated correctly.

[0007] However, the power supply control device of Patent Document 1 does not devise a solution to such a problem, and is therefore unable to solve it.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a power supply control device, a power supply control method, and a computer program that are capable of correctly estimating the wire temperature for multiple types of loads with different driving current values. [Means for solving the problem]

[0009] A power supply control device according to an embodiment of the present disclosure is a power supply control device for a vehicle that controls power supply to a load based on the temperature estimation result of an electric wire, and includes a change unit that changes parameters for the temperature estimation according to the load, and an estimation unit that performs the temperature estimation using the changed parameters.

[0010] A power supply control method according to an embodiment of the present disclosure is a power supply control method by a power supply control device for a vehicle that controls power supply to a load based on a result of estimating the temperature of an electric wire, in which a parameter for the temperature estimation is changed according to the load, the temperature estimation is performed using the changed parameter, and the power supply is turned on or off based on the result of the temperature estimation.

[0011] A computer program according to an embodiment of the present disclosure is a computer program for controlling power supply in a power supply control device for a vehicle that controls power supply to a load based on the result of estimating the temperature of an electric wire, and causes a computer to change parameters for the temperature estimation in accordance with the load, perform the temperature estimation using the changed parameters, and execute a process of turning the power supply on or off based on the result of the temperature estimation. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to accurately estimate the wire temperature even for a plurality of types of loads with different driving current values. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a conceptual diagram illustrating a power supply control device according to a first embodiment mounted on a vehicle and a load connected to the power supply control device. [Figure 2] FIG. 2 is a functional block diagram conceptually illustrating the functional processes of the microcomputer of the power supply control device. [Figure 3] 10 is a diagram conceptually illustrating an example of the contents stored in a storage unit. [Figure 4] 4 is a flowchart illustrating a process in which the power supply control device of the first embodiment controls power supply based on an estimated temperature of a load-side electric wire. [Figure 5] FIG. 10 is a conceptual diagram illustrating a power supply control device according to a second embodiment mounted on a vehicle and a load connected to the power supply control device. [Figure 6] FIG. 10 is a conceptual diagram illustrating a power supply control device according to a third embodiment mounted on a vehicle and a load connected to the power supply control device. [Figure 7] 10 is a flowchart illustrating a process for changing a power line parameter in a power supply control device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Description of the embodiment of the present invention] First, embodiments of the present disclosure will be listed and described. At least some of the embodiments described below may be combined in any desired manner.

[0015] (1) A power supply control device according to an embodiment of the present disclosure is a power supply control device for a vehicle that controls power supply to a load based on a result of estimating the temperature of an electric wire, and includes a change unit that changes parameters for the temperature estimation according to the load, and an estimation unit that performs the temperature estimation using the changed parameters.

[0016] In this embodiment, for example, when the load is replaced, the change unit changes the temperature estimation parameters in accordance with the replaced load, and the estimation unit performs the temperature estimation using the changed parameters. Therefore, even if the driving current value of the replaced load is different, the wire temperature can be accurately estimated.

[0017] (2) A power supply control device according to an embodiment of the present disclosure includes an acquisition unit that acquires specific information related to the parameter, and the change unit changes the parameter based on the specific information acquired by the acquisition unit.

[0018] In this embodiment, for example, when the load is replaced, the acquisition unit acquires specific information corresponding to the replaced load, and the change unit changes the parameter based on the specific information acquired by the acquisition unit. Therefore, even when the load is replaced, the wire temperature can be accurately estimated.

[0019] (3) In the power supply control device according to the embodiment of the present disclosure, the acquisition unit acquires the specific information from outside the vehicle via a reception unit provided in the vehicle.

[0020] In this embodiment, for example, when the load is replaced, the acquisition unit acquires specific information corresponding to the replaced load from outside the vehicle via the reception unit, and the change unit changes the parameter based on the specific information acquired by the acquisition unit. Therefore, even when the load is replaced, the wire temperature can be accurately estimated.

[0021] (4) A power supply control device according to an embodiment of the present disclosure includes a memory unit that stores the specific information corresponding to each of multiple types of loads that can be connected to the device itself, the acquisition unit acquires the specific information from a communication unit related to the load, and the change unit changes the parameters based on the specific information acquired from the communication unit and the contents stored in the memory unit.

[0022] In this embodiment, for example, when the load is replaced, the acquisition unit acquires the specific information corresponding to the replaced load from the communication unit, and the change unit changes the parameter based on the specific information acquired by the acquisition unit and the contents stored in the memory unit. Therefore, even when the load is replaced, the wire temperature can be accurately estimated.

[0023] (5) In a power supply control device according to an embodiment of the present disclosure, the specific information is at least one of a current value for driving the load, a current value related to a switch that turns the power supply on or off, and information related to the electric wire.

[0024] In this embodiment, the specific information may be, for example, a current value for driving the load, a current value flowing through a switch that turns the power supply on or off, or information related to the electric wire (for example, diameter).

[0025] (6) In a power supply control device according to an embodiment of the present disclosure, the specific information includes a current value for driving the load, and the power supply control device is equipped with a memory unit that stores the current value of each of multiple types of loads that can be connected to the device itself, and a current detection unit that detects the current value at the time of initial energization between the device itself and the load, and the change unit changes the parameter based on the acquired current value acquired from the current detection unit and the stored contents of the memory unit.

[0026] In this embodiment, for example, when the load is replaced, the acquisition unit acquires a current value for driving the replaced load from the current detection unit, and the change unit changes the parameter based on the current value acquired by the acquisition unit and the contents stored in the memory unit. Therefore, even when the load is replaced, the wire temperature can be accurately estimated.

[0027] (7) In a power supply control device according to an embodiment of the present disclosure, the acquisition unit acquires the specific information via a communication unit related to the load, and the specific information includes a current value for driving the load. The power supply control device is equipped with a current detection unit that detects the current value at the time of initial energization between the device and the load, and a judgment unit that judges whether communication with the communication unit is possible. The acquisition unit acquires the specific information from the communication unit or acquires the current value from the current detection unit depending on the judgment result of the judgment unit.

[0028] In this embodiment, for example, when the load is replaced, the determination unit determines whether communication with the communication unit is possible, and if it is determined that communication is possible, the acquisition unit acquires the specific information from the communication unit, and if it is determined that communication is not possible, the acquisition unit acquires the current value from the current detection unit. Therefore, it is possible to deal with a case where a communication unit related to the replaced load does not exist, or a case where a communication unit exists but the acquisition unit cannot acquire the specific information from the communication unit for some reason.

[0029] (8) In a power supply control device according to an embodiment of the present disclosure, the acquisition unit acquires the specific information via a communication unit related to the load, and when the acquisition unit acquires the specific information from the reception unit, the acquisition unit invalidates the specific information acquired from the communication unit.

[0030] In this embodiment, for example, when a load is replaced, the identification information is acquired via a communication unit related to the load, and when the identification information is acquired from a worker or the like via the reception unit, the acquisition unit invalidates the identification information acquired from the communication unit. The change unit changes parameters using the identification information from the reception unit, and the estimation unit performs the temperature estimation using the changed parameters. Therefore, the accuracy of the temperature estimation can be improved.

[0031] (9) A power supply control device according to an embodiment of the present disclosure includes a semiconductor switch that turns the power supply on or off, and the semiconductor switch has an on-resistance corresponding to the maximum current value among the current values ​​for driving each of multiple types of loads that can be connected to the device.

[0032] In this embodiment, the semiconductor switch has an on-resistance corresponding to the maximum current value, so that the semiconductor switch and the output wire can be replaced to accommodate any load.

[0033] (10) A power supply control method according to an embodiment of the present disclosure is a power supply control method by a power supply control device for a vehicle that controls power supply to a load based on a result of estimating the temperature of an electric wire, in which a parameter for the temperature estimation is changed according to the load, the temperature estimation is performed using the changed parameter, and the power supply is turned on or off based on the result of the temperature estimation.

[0034] (11) A computer program according to an embodiment of the present disclosure is a computer program for controlling power supply in a vehicle power supply control device that controls power supply to a load based on a result of estimating the temperature of an electric wire, and causes a computer to change parameters for the temperature estimation in accordance with the load, perform the temperature estimation using the changed parameters, and turn the power supply on or off based on the result of the temperature estimation.

[0035] In this embodiment, for example, when the load is replaced, the temperature estimation parameters are changed according to the replaced load, and the temperature estimation is performed using the changed parameters. Therefore, even if the driving current value of the replaced load is different, the wire temperature can be estimated correctly.

[0036] [Details of the embodiment of the present invention] A power supply control device, a power supply control method, and a computer program according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0037] (Embodiment 1) Conventionally, in a vehicle, a power supply control device is interposed between a power source such as a battery and a load such as a seat or a door. The power supply control device is a device that turns on or off the power supply from the power source to the load as needed.

[0038] The power supply control device has a fuse that cuts off the power supply to the load. For example, if the temperature of the electric wire rises excessively due to a short circuit current that repeatedly turns on and off, the fuse cuts off the power supply to the load to prevent the electric wire from smoking.

[0039] In recent years, power supply control devices have been equipped with semiconductor switches as fuses, which estimate the temperature of the electric wire when power is applied and compare the estimated temperature with the upper limit temperature allowed for the electric wire, so that the semiconductor switch cuts off the power supply before the electric wire reaches the smoking temperature.

[0040] A known method for estimating the temperature of an electric wire when it is energized is to estimate the temperature of the electric wire from the sum of the heat generated and the heat dissipated by the electric wire. Specifically, the temperature of the electric wire can be estimated by detecting the current in the electric wire when it is energized using the following equation 1. ΔTw = A×I 2 ×{1-exp(-t / τ)}···Formula 1 ΔTw: Temperature rise of the wire from the reference temperature (℃) I: Detected current value (A) τ: Thermal time constant of the wire (s) (fixed value) t: time (s) A: Wire parameters

[0041] Here, A is a characteristic of the wire connected to the load corresponding to the power supply control device. That is, the wire parameter A varies depending on the wire connected to the load. For example, the wire parameter A is a fixed value that depends on Rw (wire resistance (Ω)) and Rthw (wire thermal resistance (°C / W).

[0042] However, the type of wire connected to the load, for example, the wire thickness (diameter), is determined by the drive current required to drive the load. That is, the larger the drive current, the larger the diameter of the wire required. Furthermore, the upper limit temperature that the wire can tolerate varies depending on the type of wire. Furthermore, the drive current value differs depending on whether the load is a seat or a door. Even for the same seat, the drive current value differs depending on whether it has a USB (Universal Serial Bus) charging function, a heater function, a power seat function, and so on.

[0043] As described above, the type of wire (wire diameter) is determined depending on the load, so when the power supply control device is mounted on a vehicle, the setting of the wire parameter A of the power supply control device is determined depending on the load connected to the power supply control device.

[0044] Furthermore, it is necessary to select different diameters of wires connected to loads depending on the loads that are expected to be connected, and it is also necessary to select semiconductor switches with different capacities for the power supply control devices. In other words, it is necessary to prepare in advance multiple types of power supply control devices with semiconductor switches of different capacities, which increases the number of product varieties for power supply control devices.

[0045] Furthermore, it is conceivable that after the power supply control device is installed in the vehicle, i.e., after shipping from the factory, a load function or a load itself may be added. In this case, the drive current value increases with the addition of the load function or the addition of the load itself, and therefore it becomes necessary to change to an electric wire with a larger diameter. That is, even though the electric wire parameter A in the above-mentioned formula 1 actually changes because the electric wire (electric wire diameter) has changed, the electric wire parameter A of the power supply control device remains set at the time of shipping, and the power supply control device may not be able to accurately estimate the temperature of the electric wire, which may result in malfunction.

[0046] In contrast to this, the power supply control device of the first embodiment described below is configured to solve the above-mentioned problems, as will be explained in detail below.

[0047] 1 is a conceptual diagram illustrating a power supply control device 10 according to a first embodiment mounted on a vehicle C and a load 52 connected to the power supply control device 10. The load 52 is, for example, at least one of a USB charger, a heater, and a power seat motor provided in a seat 50.

[0048] The vehicle C includes a power source 20, a power supply control device 10, and a seat 50. The seat 50 has a load 52, and the power supply control device 10 is interposed between the power source 20 and the load 52. In other words, the power source 20 is connected to the load 52 via the power supply control device 10.

[0049] A connector 40 is interposed between the power supply control device 10 and the seat 50 (load 52). The power supply control device 10 and the connector 40 are connected by a power supply wire L1 (output wire), and the connector 40 and the load 52 are connected by a power supply wire L3. For example, the connector 40 is disposed at the boundary between the floor and the seat 50 of the vehicle C, with the upstream side of the connector 40 being the power source 20 side and the downstream side of the connector 40 being the load side. Hereinafter, the wire L1 will also be referred to as the power supply side wire L1, and the wire L3 will also be referred to as the load side wire L3.

[0050] The wire diameter of the load-side wire L3 is equal to or smaller than the wire diameter of the power-source-side wire L1. Specifically, the power-source-side wire L1 has a wire diameter corresponding to the drive current value of the load with the largest drive current value among all loads expected to be connected to the power supply control device 10. For example, if loads 1 to 4 with different drive current values ​​can be connected to the power supply control device 10 and load 4 has the largest drive current value, the power-source-side wire L1 has a wire diameter corresponding to the drive current value of load 4.

[0051] Therefore, as described above, when a load function or a load itself is added, the load-side electric wire L3 must also be replaced, but the power-supply-side electric wire L1 does not need to be replaced.

[0052] The power supply control device 10 and the connector 40 are connected by a communication line L2. Hereinafter, the communication line L2 will also be referred to as the power supply side communication line L2.

[0053] A reception unit 30 is connected to the power supply side communication line L2, and receives input of load information (specific information) from outside the vehicle C. Here, the load information is information related to the electric wire parameter A, such as information that identifies the load 52 connected to the power supply control device 10. Specifically, the load information may be data representing the product number of the load 52, data representing the drive current value related to the load 52, or data representing the wire diameter of the load side electric wire L3 corresponding to the drive current value. Furthermore, the load information may be data representing Rw and Rthw.

[0054] The receiving unit 30 receives input of the load information when the vehicle C is shipped, or receives input of the load information from a vehicle maintenance company, including an authorized dealer, that performs maintenance work on the vehicle C, such as replacing the ECU. Furthermore, the reception unit 30 may be configured to have a communication unit (not shown) and to receive load information from outside the vehicle C via wireless communication using OTA (Over The Air) technology. In the following, for the sake of convenience, it is assumed that the receiving unit 30 receives input of load information from a vehicle maintenance company, and that such load information is the drive current value related to the load 52.

[0055] The power supply control device 10 includes a microcomputer 11, an IPS (Intelligence Power Switch) 13, and an I / O (Input / Output Interface) 12. The IPS 13 is interposed between the power supply 20 and the I / O 12.

[0056] The I / O 12 is connected to the power supply side electric wire L1 and the power supply side communication wire L2. That is, the current flowing from the power supply 20 to the I / O 12 via the IPS 13 flows to the power supply side electric wire L1. In addition, the load information received by the reception unit 30 is sent to the I / O 12 via the power supply side communication wire L2, and then sent from the I / O 12 to the microcomputer 11.

[0057] The IPS 13 includes a switch element 131 and a current detection circuit 132 . The switch element 131 is a semiconductor switch element such as an n-channel MOSFET, and turns on or off the current from the power supply 20 to the load 52, that is, the current that flows from the power supply 20 to the load 52 when the load 52 is energized (hereinafter referred to as the energizing current I). The switch element 131 turns on or off the above-mentioned energizing current I in response to an instruction from the microcomputer 11.

[0058] Furthermore, as described above, the power supply side wire L1 has a wire diameter corresponding to the largest expected drive current value of the load, and therefore the switch element 131 also has an on-resistance corresponding to the largest expected drive current value of the load.

[0059] The current detection circuit 132 is, for example, a sense MOSFET, and detects the current value of the current I when the current is applied, and sends the detected value to the microcomputer 11.

[0060] FIG. 2 is a functional block diagram conceptually illustrating the functional processes of the microcomputer 11 of the power supply control device 10. As shown in FIG. The microcomputer 11 includes a memory unit 111, an estimation unit 112, a change unit 113, an acquisition unit 114, an instruction unit 115, and a determination unit 116. In other words, the microcomputer 11 has processing circuits that function as the memory unit 111, the estimation unit 112, the change unit 113, the acquisition unit 114, the instruction unit 115, and the determination unit 116.

[0061] The storage unit 111 stores the above-mentioned formula 1. It also stores a plurality of types of loads connectable to the power supply control device 10 and the load information for each load in association with each other. FIG. 3 is a diagram conceptually illustrating an example of the contents stored in the storage unit 111. In FIG. For example, as described above, it is assumed that loads 1 to 4 with different drive current values ​​can be connected to the power supply control device 10. In this case, the storage unit 111 stores a range of drive current values ​​and a wire parameter A associated with each of the loads 1 to 4. Hereinafter, it is assumed that the wire parameter A has the relationship "A = Rw × Rthw." That is, the wire parameter A is the product of the wire resistance and the wire thermal resistance of the load-side wire. The storage unit 111 also stores an upper limit temperature in association with each of the loads 1 to 4. Here, the upper limit temperature is an upper limit temperature allowed for each load-side electric wire L3 determined according to the load.

[0062] The estimation unit 112 estimates the temperature of the load-side electric wire L3. That is, the estimation unit 112 estimates the temperature of the load-side electric wire L3 using the above-described formula 1. More specifically, the estimation unit 112 estimates the temperature of the load-side electric wire L3 using the reference temperature at the start of the temperature estimation, which is set by a reference temperature setting circuit (not shown), and formula 1.

[0063] More specifically, the current detection circuit 132 detects the current value of the current I supplied to the load 52 via the load side wire L3 at predetermined time intervals, and the estimation unit 112 calculates the temperature rise (ΔTw) from the reference temperature of the load side wire L3 within the predetermined time period caused by the detected current I, and adds the temperature rise to the reference temperature to estimate the temperature of the load side wire L3.

[0064] The acquisition unit 114 acquires load information related to the load 52 from outside the power supply control device 10. The acquisition unit 114 monitors the I / O 12 and acquires the load information sent from the reception unit 30. For example, when the reception unit 30 receives data indicating a drive current value related to the load 52 from a vehicle maintenance shop, the reception unit 30 transmits the received drive current value to the I / O 12. The I / O 12 transmits the received drive current value to the acquisition unit 114.

[0065] The change unit 113 changes the parameter related to the temperature estimation of the load-side electric wire L3 in accordance with the load 52. For example, when the acquisition unit 114 acquires load information related to the load 52 from outside the power supply control device 10, the change unit 113 changes the electric wire parameter A based on the load information acquired by the acquisition unit 114 and the stored contents of the storage unit 111. When the change unit 113 changes the electric wire parameter A, the estimation unit 112 estimates the temperature of the load-side electric wire L3 using the changed electric wire parameter A.

[0066] The determination unit 116 compares the temperature of the load side electric wire L3 estimated by the estimation unit 112 (hereinafter referred to as the estimated temperature of the load side electric wire L3) with the upper limit temperature stored in the memory unit 111, and determines whether the estimated temperature of the load side electric wire L3 is equal to or higher than the upper limit temperature.

[0067] When the determining unit 116 determines that the estimated temperature of the load-side electric wire L3 is equal to or higher than the upper limit temperature, the instructing unit 115 instructs the switch element 131 of the IPS 13 to turn off the current I.

[0068] As described above, the sheet 50 is connected to the connector 40 via the load-side wire L3. The sheet 50 has a switch 51 and a load 52. The switch 51 is interposed between the connector 40 and the load 52.

[0069] Hereinafter, the processing of the power supply control device 10 of the first embodiment when the load 52 in the vehicle C is changed will be described. FIG. 4 is a flowchart illustrating a process in which the power supply control device 10 of the first embodiment controls power supply based on the estimated temperature of the load-side electric wire L3.

[0070] For example, a vehicle maintenance shop may, as necessary, replace the load 52 attached to the seat 50 of the vehicle C from load 1 with load 2 having a larger drive current value. The vehicle maintenance shop first turns off the switch 51, replaces the load 1 with load 2, and then turns on the switch 51. In this case, since the drive current value increases with the change in load 52, the vehicle maintenance shop also changes the load side electric wire L3 to a load side electric wire L3 having a larger electric wire diameter.

[0071] Since the electric wire (electric wire diameter) has changed in this way, the electric wire parameter A in the above-mentioned formula 1 also needs to be changed. Therefore, the vehicle maintenance shop inputs load information of the new load 52 after the change through the receiving unit 30. For example, the vehicle maintenance shop inputs a drive current value (data) related to the new load 52, which is then received by the receiving unit 30 (step S101).

[0072] When the reception unit 30 receives a drive current value for a new load 52 from a vehicle maintenance company, it transmits the received drive current value to I / O 12, and the acquisition unit 114 acquires the drive current value via I / O 12 (step S102).

[0073] In this way, when the acquisition unit 114 acquires a drive current value related to a new load 52, the change unit 113 changes the wire parameter A based on the drive current value acquired by the acquisition unit 114 and the contents stored in the memory unit 111 (step S103).

[0074] In this example, since the load has been changed from load 1 to load 2, the drive current value acquired by the acquisition unit 114 is within the range of 5 A to 10 A. Therefore, based on the table of FIG. 3 stored in the storage unit 111, the change unit 113 replaces the wire parameter A in Equation 1 from the current wire parameter A corresponding to load 1 with the wire parameter A corresponding to load 2.

[0075] Thereafter, the current detection circuit 132 detects the current value of the energizing current I supplied to the load 52 via the load-side electric wire L3 (step S104), and transmits the detected current value of the energizing current I to the microcomputer 11.

[0076] When the current value of the energizing current I is received, the estimation unit 112 estimates a new temperature of the load side electric wire L3 using the current value of the energizing current I and the above-mentioned formula 1 in which the electric wire parameter A has been changed (step S105). The estimation of the temperature of the load side electric wire L3 has already been described, and a detailed description thereof will be omitted.

[0077] When the temperature of the load side electric wire L3 is estimated, the determination unit 116 determines whether the estimated temperature of the load side electric wire L3 is equal to or higher than the upper limit temperature based on the upper limit temperature stored in the storage unit 111 (step S106). When the determination unit 116 determines that the estimated temperature of the load side electric wire L3 is lower than the upper limit temperature (step S106: NO), the process returns to step S104. For example, when the determination unit 116 determines that the estimated temperature of the load side electric wire L3 is lower than the upper limit temperature, the process may be configured to return to step S104 after a predetermined time has elapsed.

[0078] On the other hand, if the determination unit 116 determines that the estimated temperature of the load side electric wire L3 is equal to or higher than the upper limit temperature (step S106: YES), the instruction unit 115 instructs the switch element 131 of the IPS 13 to turn off the current I (step S107).

[0079] Through the above process, when the load 52 is changed, the power supply control device 10 of the first embodiment estimates the temperature of the load-side electric wire L3 using the load information of the new load 52, as described above. Therefore, even when the load 52 is changed, the temperature of the load-side electric wire L3 can be accurately estimated. Therefore, even when a function of the load 52 of the vehicle C is added after factory shipment, or when the load 52 itself is added, smoking in the load-side electric wire L3 is prevented in advance.

[0080] Furthermore, as described above, when the load 52 is changed, the power supply control device 10 of embodiment 1 changes the existing electric wire parameter A to the electric wire parameter A corresponding to the new load 52 using the load information of the new load 52 received from outside the power supply control device 10 via the receiving unit 30. Therefore, it is possible to accommodate replacement with different types of loads 52, and there is no need to prepare separate power supply control devices 10 in advance that are compatible with multiple types of loads 52 that can be connected to the power supply control device 10, thereby reducing the manufacturing cost of the power supply control device 10.

[0081] (Embodiment 2) 5 is a conceptual diagram illustrating a power supply control device 10 according to the second embodiment mounted on a vehicle C and a load 52 connected to the power supply control device 10. As in the first embodiment, the vehicle C includes a power source 20, a power supply control device 10, and a seat 50, but does not include a reception unit 30.

[0082] The power supply control device 10 is interposed between the power source 20 and the load 52. In addition, a connector 40 is interposed between the power supply control device 10 and the seat 50. The power source 20, the power supply control device 10, and the connector 40 are the same as those in the first embodiment, and detailed description thereof will be omitted.

[0083] Meanwhile, the seat 50 is connected to the connector 40 via a load-side electric wire L3 for power supply. The seat 50 and the connector 40 are also connected by a communication line L4. That is, in the power supply control device 10 of the second embodiment, the power supply-side communication line L2 connects the power supply control device 10 and the connector 40 upstream of the connector 40, and the communication line L4 connects the connector 40 and the seat 50 downstream of the connector 40. Hereinafter, the communication line L4 will also be referred to as the load-side communication line L4.

[0084] The seat 50 has an ECU (Electronic Control Unit) 53 and a load 52. The ECU 53 (communication unit) is interposed between the connector 40 and the load 52. That is, the ECU 53 and the connector 40 are connected by a load-side electric wire L3 and a load-side communication line L4. In other words, the ECU 53 can communicate with the power supply control device 10 via the load-side communication line L4, the connector 40, and the power-source-side communication line L2.

[0085] The ECU 53 controls the supply of current to the load 52. The ECU 53 also stores load information that identifies the load 52, and transmits the load information to the power supply control device 10 in response to a request from the power supply control device 10, as will be described later.

[0086] The load information may be, for example, data representing the product number of the load 52, data representing the drive current value related to the load, data representing the wire diameter of the load-side wire L3 corresponding to the drive current value, or data representing Rw and Rthw. For convenience, the following description will be given taking as an example a case where the load information is data representing the drive current value.

[0087] For example, a vehicle maintenance shop may, as necessary, replace the load 52 attached to the seat 50 of the vehicle C from the load 1 with the load 2 having a larger drive current value. In this case, since the drive current value increases with the change in the load 52, the vehicle maintenance shop also changes the load side electric wire L3 to a load side electric wire L3 having a larger electric wire diameter.

[0088] The following describes the processing of the power supply control device 10 of the second embodiment when the load 52 is changed in the vehicle C as described above.

[0089] When the load 52 is replaced from the load 1 to the load 2, the microcomputer 11 of the power supply control device 10 requests the ECU 53 of the seat 50 to send the load information of the load 52. In response to this, the ECU 53 transmits the load information of the load 52 to the power supply control device 10. At this time, the ECU 53 may transmit the load information (drive current value) of the load 52 stored in the own device to the power supply control device 10, or may detect the current value of the energizing current I flowing in the own device and transmit the detected information to the power supply control device 10.

[0090] When data indicating the drive current value of the load 52 is sent from the ECU 53 of the seat 50, the power supply control device 10 performs the processes from step S102 to step S107 in FIG. 4, similarly to the first embodiment.

[0091] That is, the acquisition unit 114 acquires a drive current value from the ECU 53 via the I / O 12, and the change unit 113 changes the wire parameter A based on the drive current value acquired by the acquisition unit 114 and the stored contents of the storage unit 111. Thereafter, the current detection circuit 132 detects the current value of the energizing current I supplied to the load 52 through the load-side wire L3, and the estimation unit 112 estimates a new temperature of the load-side wire L3 using the current value of the energizing current I and the above-mentioned Equation 1 in which the wire parameter A has been changed. Then, the determination unit 116 determines whether the estimated temperature of the load-side wire L3 is equal to or higher than the upper limit temperature (see the table in FIG. 3 ) based on the upper limit temperature stored in the storage unit 111. If the determination unit 116 determines that the estimated temperature of the load-side wire L3 is equal to or higher than the upper limit temperature, the instruction unit 115 instructs the switch element 131 of the IPS 13 to turn off the energizing current I.

[0092] As a result of having the above-described configuration, the power supply control device 10 of embodiment 2, like embodiment 1, can accurately estimate the temperature of the load side wire L3 even in cases where the function of the load 52 of the vehicle C is added after shipment from the factory, or even if the load 52 itself is added, thereby preventing smoke from being generated in the load side wire L3.

[0093] Furthermore, when the load 52 is changed, the existing electric wire parameter A is accordingly changed to an electric wire parameter A corresponding to the new load 52. This allows for replacement with a different type of load 52, and eliminates the need to prepare separate power supply control devices 10 in advance that are compatible with multiple types of loads 52 that can be connected to the power supply control device 10, thereby reducing the manufacturing cost of the power supply control device 10.

[0094] In the above, an example has been described in which the power supply control device 10 of embodiment 2 does not have a receiving unit 30 and acquires load information of the load 52 only from the ECU 53, but this is not limited to this and the power supply control device 10 may also be configured to have a receiving unit 30.

[0095] In this way, when the power supply control device 10 has both the ECU 53 and the reception unit 30, the power supply control device 10 is configured to preferentially acquire load information via the reception unit 30. For example, when the acquisition unit 114 of the power supply control device 10 acquires the load information from outside the vehicle C via the reception unit 30, the acquisition unit 114 invalidates the load information acquired from the ECU 53.

[0096] That is, the load information received from the vehicle maintenance shop or the load information received via OTA is used preferentially for estimating the temperature of the load-side electric wire L3, thereby improving the accuracy of the temperature estimation.

[0097] The same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

[0098] (Embodiment 3) 6 is a conceptual diagram showing a power supply control device 10 according to the third embodiment mounted on a vehicle C and a load 52 connected to the power supply control device 10. As in the first embodiment, the vehicle C includes a power source 20, a power supply control device 10, and a seat 50, but does not include a reception unit 30. Other aspects are the same as those in the first embodiment, and detailed description thereof will be omitted.

[0099] For example, a vehicle maintenance shop may, as necessary, replace the load 52 attached to the seat 50 of the vehicle C from the load 1 with the load 2 having a larger drive current value. In this case, since the drive current value increases with the change in the load 52, the vehicle maintenance shop also changes the load side electric wire L3 to a load side electric wire L3 having a larger electric wire diameter.

[0100] The following describes the processing of the power supply control device 10 of the third embodiment when the load 52 is changed in the vehicle C as described above.

[0101] In the case of replacing load 1 with load 2, the vehicle maintenance shop replaces load 1 with load 2 and then turns on switch 51. This enables power supply from power source 20 to load 52.

[0102] For example, when the engine of the vehicle C starts, a current I flows from the power source 20 to the load 52. The power supply control device 10 of the third embodiment changes the electric wire parameter A based on the current value of the current I when the power supply control device 10 itself and the load 52 are energized for the first time (hereinafter referred to as the initial energization) and the contents stored in the memory unit 111.

[0103] That is, when current is first applied between the power supply control device 10 and the load 52, the current detection circuit 132 detects the current value of the current flow I and sends the detected current value of the current flow I to the microcomputer 11 (acquisition unit 114). As a result, the acquisition unit 114 acquires the current value of the current flow I at the time of the initial current application as load information. Hereinafter, the current value of the current flow I acquired by the acquisition unit 114 will be referred to as the acquired current flow I (acquired current value).

[0104] When the obtained energizing current I is sent from the current detection circuit 132, the microcomputer 11 performs the processes from step S102 to step S107 in FIG.

[0105] That is, the acquisition unit 114 acquires the acquired energization current I from the current detection circuit 132, and the change unit 113 changes the wire parameter A based on the acquired energization current I acquired by the acquisition unit 114 and the stored contents of the storage unit 111. That is, the change unit 113 replaces the current wire parameter A with the wire parameter A corresponding to the range of drive current values ​​to which the acquired energization current I belongs in the stored contents of the storage unit 111 (see the table in FIG. 3 ).

[0106] Thereafter, the estimation unit 112 estimates a new temperature of the load-side electric wire L3 using the acquired current flow I and the above-described formula 1 in which the electric wire parameter A has been changed. Then, the determination unit 116 determines whether the estimated temperature of the load-side electric wire L3 is equal to or higher than the upper limit temperature based on the upper limit temperature stored in the storage unit 111. If the determination unit 116 determines that the estimated temperature of the load-side electric wire L3 is equal to or higher than the upper limit temperature, the instruction unit 115 instructs the switch element 131 of the IPS 13 to turn off the current flow I.

[0107] As a result of having the above-described configuration, the power supply control device 10 of embodiment 3, like embodiment 1, can accurately estimate the temperature of the load side wire L3 even if the load 52 of the vehicle C is changed after leaving the factory, thereby preventing smoke from being generated in the load side wire L3.

[0108] Furthermore, when the load 52 is changed, the existing electric wire parameter A is accordingly changed to an electric wire parameter A corresponding to the new load 52. This eliminates the need to prepare separate power supply control devices 10 in advance that are compatible with multiple types of loads 52 that can be connected to the power supply control device 10, thereby reducing the manufacturing cost of the power supply control device 10.

[0109] The same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

[0110] (Embodiment 4) As described above, in the second embodiment, an example is described in which the load information (drive current value) is acquired from the ECU 53 and the wire parameter A is changed, and in the third embodiment, an example is described in which the load information (acquired energization current I) is acquired from the current detection circuit 132 at the time of the first energization and the wire parameter A is changed, but the present invention is not limited to these. For example, the source of the load information may be changed depending on the situation.

[0111] FIG. 7 is a flowchart illustrating the process of changing the electric wire parameter A in the power supply control device 10 of the fourth embodiment. In the power supply control device 10 of the fourth embodiment, the acquisition unit 114 is configured to be able to acquire load information (drive current value) from the ECU 53, and also to acquire load information (acquired energization current I) from the current detection circuit 132. That is, the power supply control device 10 of the fourth embodiment is equipped with the current detection circuit 132, similar to Fig. 5, and is connected to the seat 50 having the ECU 53 and the load 52. Fig. 5 has already been described, and a detailed description thereof will be omitted.

[0112] For example, suppose that a vehicle maintenance shop replaces the load 52 of the seat 50 of the vehicle C as needed, and along with the replacement of the load 52, also changes the load side electric wire L3 to a load side electric wire L3 with a larger electric wire diameter.

[0113] After the vehicle maintenance company has completed the replacement of the load 52, the determination unit 116 of the power supply control device 10 determines whether or not communication with the ECU 53 of the load 52 is possible (step S201). In other words, the determination unit 116 determines whether or not the ECU 53 of the load 52 exists. More specifically, the microcomputer 11 transmits a signal to the seat 50 requesting a response, and monitors the I / O 12 for a predetermined period of time to see if a response signal in response to the request is received.

[0114] If the response signal is received within a predetermined time, the determination unit 116 determines that communication with the ECU 53 of the load 52 is possible (step S201: YES), and the microcomputer 11 requests the ECU 53 of the seat 50 to send load information of the load 52. In response to the request, the ECU 53 transmits the load information of the load 52 to the power supply control device 10, and the acquisition unit 114 acquires the drive current value from the ECU 53 via the I / O 12 (step S205). The process of the acquisition unit 114 acquiring the drive current value from the ECU 53 has already been described in the second embodiment, and a detailed description thereof will be omitted. Thereafter, the process proceeds to step S204.

[0115] On the other hand, if the response signal is not received within the predetermined time, the determination unit 116 determines that communication with the ECU 53 of the load 52 is not possible (step S201: NO). In other words, the determination unit 116 determines that the ECU 53 of the load 52 does not exist.

[0116] Next, the determination unit 116 determines whether or not the initial energization has occurred between the power supply control device 10 and the load 52 (step S202). If the determination unit 116 determines that the initial energization has not occurred between the power supply control device 10 and the load 52 (step S202: NO), the determination unit 116 waits until the initial energization occurs.

[0117] Furthermore, if the determination unit 116 determines that the initial energization has occurred between the power supply control device 10 and the load 52 (step S202: YES), the current detection circuit 132 detects the current value of the energization current I and sends the detected current value of the energization current I to the acquisition unit 114 of the microcomputer 11, which then acquires the current value of the energization current I at the time of the initial energization (step S203). The process by which the acquisition unit 114 acquires the current value of the energization current I at the time of the initial energization has already been described in the third embodiment, and a detailed description thereof will be omitted. Thereafter, the process proceeds to step S204.

[0118] Through the above process, the acquisition unit 114 can acquire the load information (the drive current value or the current value of the energizing current I) of the new load 52. Next, the change unit 113 changes the electric wire parameter A based on the load information acquired by the acquisition unit 114 and the stored contents of the storage unit 111 (step S204). The change of the electric wire parameter A has already been described, and a detailed description thereof will be omitted.

[0119] As described above, the power supply control device 10 of the fourth embodiment can change the source of the load information depending on the situation. Therefore, the load information can be acquired even when communication with the ECU 53 of the load 52 is impossible or when the ECU 53 of the load 52 does not exist.

[0120] With the above-described configuration, the power supply control device 10 of the fourth embodiment also achieves the same effects as the first embodiment.

[0121] Detailed explanations of the same parts as in the first embodiment will be omitted.

[0122] In the above, the case where the wire parameter A is the product of Rw (wire resistance) and Rthw (wire thermal resistance) has been described as an example, but the present invention is not limited to this. For example, the wire parameter A may be either Rw or Rthw.

[0123] Furthermore, although the above description has been given taking an example where one load 52 is connected to the power supply control device 10, the present invention is not limited to this, and similar effects can be achieved even when multiple loads 52 are connected to the power supply control device 10. In this case, the load-side electric wire is determined according to the sum of the drive current values ​​of the multiple loads 52 connected to the power supply control device 10, so the electric wire parameter A can be set using Rw and Rthw related to the load-side electric wire corresponding to the sum of the drive current values ​​of the multiple loads 52.

[0124] In the above, an example in which an n-channel MOSFET is used as the switch element 131 has been shown, but the present invention is not limited to this. For example, a p-channel MOSFET or a bipolar transistor may be used as the switch element 131.

[0125] In the above example, the current value of the energizing current I is detected by the current detection circuit 132, which is a sense MOSFET. However, the present invention is not limited to this. For example, the current value of the energizing current I may be detected using a shunt resistor.

[0126] The technical features (constituent elements) described in the first to fourth embodiments can be combined with each other, and by combining them, new technical features can be formed. The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. 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 meaning and scope of the claims.

[0127] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any and all combinations, regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used. [Explanation of symbols]

[0128] 10 Power supply control device 11 Microcomputer 12 I / O 13 IPS 20 Power supply 30 Reception 40 connectors 50 sheets 51 Switch 52 Load 53 ECU 111 Storage section 112 Estimation Department 113 Changes 114 Acquisition Department 115 Instruction section 116 Judgment section 131 Switching element 132 Current detection circuit A Wire parameters C vehicle I Carrying current L1,L3 electric wire L2, L4 communication lines

Claims

1. A power supply control device for a vehicle that controls power supply to a load based on a result of estimating the temperature of an electric wire, an acquisition unit that acquires specific information related to the parameters of the temperature estimation from outside the vehicle; a change unit that changes the parameter in accordance with the load; an estimation unit that estimates the temperature using the changed parameters; The change unit changes the parameter based on the specific information acquired by the acquisition unit.

2. The power supply control device according to claim 1 , wherein the acquisition unit acquires the specific information from outside the vehicle via a reception unit provided in the vehicle.

3. a storage unit that stores the specific information corresponding to each of a plurality of types of loads that can be connected to the device itself; the acquisition unit acquires the specific information from a communication unit related to the load, The power supply control device according to claim 1 , wherein the change unit changes the parameter based on the specific information acquired from the communication unit and the stored contents of the storage unit.

4. 3. The power supply control device according to claim 2, wherein the specific information is at least any one of a current value for driving the load, a current value related to a switch that turns the power supply on or off, and information related to the electric wire.

5. A power supply control device for a vehicle that controls power supply to a load based on a result of estimating the temperature of an electric wire, an acquisition unit that acquires specific information related to a parameter of the temperature estimation; a change unit that changes the parameter in accordance with the load; an estimation unit that estimates the temperature using the changed parameters; the change unit changes the parameter based on the specific information acquired by the acquisition unit; the specific information includes a current value for driving the load, a storage unit that stores the current values ​​of a plurality of types of loads that can be connected to the device itself; a current detection unit that detects a current value at the time of initial energization between the device itself and the load; The change unit changes the parameter based on the current value acquired from the current detection unit and the stored content of the storage unit.

6. the acquisition unit acquires the specific information via a communication unit related to the load; the specific information includes a current value for driving the load, a current detection unit that detects a current value when current is first applied between the device and the load, and a determination unit that determines whether communication with the communication unit is possible; The power supply control device according to claim 1 , wherein the acquisition unit acquires the specific information from the communication unit or acquires a current value from the current detection unit, depending on the determination result of the determination unit.

7. the acquisition unit acquires the specific information via a communication unit related to the load; The power supply control device according to claim 2 , wherein the acquisition unit invalidates the identification information acquired from the communication unit when the acquisition unit acquires the identification information from the reception unit.

8. a semiconductor switch that turns the power supply on or off; The power supply control device according to claim 1 , wherein the semiconductor switch has an on-resistance corresponding to a maximum current value among current values ​​for driving each of a plurality of types of loads connectable to the device itself.

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