ONBOARD CONNECTION SYSTEM AND ONBOARD SYSTEM DESIGN METHOD

A zone ECU is disposed in each of a plurality of regions partitioned on a vehicle, and each zone ECU controls a first device disposed in the same region. Independent ECUs are disposed, and each of the independent ECUs controls a second device of a function group independent of the control performed by the zone ECU without relation to the partition of the regions. A central ECU for managing the zone ECU in each of the regions and the independent ECUs is disposed. An onboard power supply is connected to power supply inputs of the zone ECUs and the central ECU Via a first power supply connection path, and the onboard power supply is connected to power supply inputs of the independent ECUs via a second power supply connection path. Power supply electric power to the second device is supplied from the independent ECUs.

TECHNICAL FIELD

The present disclosure relates to an onboard connection system and an onboard system design method.

BACKGROUND ART

Generally, in a vehicle, onboard devices such as various types of electrical components are disposed in various portions of a vehicle body in a dispersed state. In addition, for example, a large number of independent electronic control units (ECUs) are mounted for each region of the vehicle body or each function. Further, a power supply such as an onboard battery and each electronic control unit are connected via a power supply line, and a plurality of electronic control units are connected via a signal line or a communication line. Further, the power supply line, the signal line, the communication line, and the like are normally included in a wire harness routed to each part of the vehicle body.

For example, FIGS. 1 and 2 of Patent Literature 1 show an onboard system that connects zone ECUs, a central processing unit, a battery, and a large number of devices.

Further, for example, FIG. 2 of Patent Literature 2 shows an onboard system that connects a central ECU, a plurality of zone ECUs, and various devices.

Further, for example, FIG. 1 of Patent Literature 3 shows an onboard system that connects a central gateway, a plurality of zone ECUs, and various devices.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

As disclosed in Patent Literatures 1 to 3, by disposing the zone ECU for each region of the vehicle, it is easy to intensively manage various devices on the vehicle for each region. In addition, since the zone ECU and the devices as control targets are present in the same region, the length of the wire harness connecting the zone ECU and the devices can be shortened. In addition, by intensively managing the plurality of zone ECUs by the central ECU, it is easy to perform communication between a plurality of regions and management of safe communication with the outside of the vehicle.

In addition, a system configuration is also conceivable in which a central ECU is provided with a function corresponding to a human brain, for example, advanced processes such as “recognition”, “determination”, and “instruction”, and each zone ECU is provided with a control function corresponding to a human limb, for example, functions such as “detection”, “report”, and “operation according to an instruction”.

Incidentally, in recent years, the number and types of functions that are provided as standard and the number and types of functions that are selectively provided as options on the vehicle tend to further increase. Therefore, each zone ECU and the central ECU tend to increase in size. Further, as the outer size of the entire wire harness connecting the onboard battery, the zone ECUs, and the central ECU increases, the number of electric wires included in the wire harness tends to increase, and a diameter of each electric wire such as a power supply line tends to increase.

Therefore, it may be difficult to secure a wide space required for providing the zone ECUs and the central ECU. For example, large-sized zone ECUs and a central ECU may compress a limited space in a vehicle cabin. Further, it is also difficult to secure a wide space required for routing the thick wire harness. In addition, since the thick wire harness is difficult to be bent, it is difficult to perform an attachment operation when the wire harness is routed on the vehicle.

Further, when the wire harness is designed for each vehicle, various trial and error studies may be performed on the system configuration, and optimization design work is often difficult.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide an onboard connection system and an onboard system design method that facilitate miniaturization of each zone ECU and reduction in diameter of a wire harness.

The above object according to the present disclosure is achieved by the following configuration.

An onboard connection system includes:at least one zone ECU that is disposed in one region of partitioned regions on a vehicle and that controls a first device disposed in the same region;at least one independent ECU that controls a second device independent of the control performed by the zone ECU without relation to the partition of the region in which the first device is disposed, the second device being disposed in one of the regions;a central ECU that manages the zone ECU and the independent ECU, respectively;a first power supply connection path that connects an onboard power supply and each of power supply inputs of the zone ECU and the central ECU; anda second power supply connection path that is a path independent of the first power supply connection path and that connects the onboard power supply and a power supply input of the independent ECU, whereinpower supply electric power to the second device is supplied from the independent ECU.

An onboard system design method includes:determining a plurality of regions formed by partitioning a space on a vehicle;determining, regarding each of the regions, disposition of zone ECUs each of which controls all devices disposed in the corresponding region as control targets;determining disposition of a central ECU having a function of integrally managing a plurality of the zone ECUs;determining, regarding each of the plurality of regions, a routing path of a first connection circuit that connects each of all the devices disposed in the corresponding region to the corresponding zone ECU;selectively extracting, as an independent function, a function separable from the control targets of the zone ECU among the devices in each of the plurality of regions;determining an independent ECU that controls the independent function as a control target;separating a power supply connection path at a portion corresponding to the independent function assigned to the independent ECU in the first connection circuit from the zone ECU and transferring the power supply connection path to the independent ECU; andreflecting a situation after the transferring of the power supply connection path and optimizing a configuration of a power supply connection circuit in at least a part of a wire harness.

According to the onboard connection system and the onboard system design method of the present disclosure, the miniaturization of each zone ECU and the reduction in diameter of the wire harness are facilitated.

The present disclosure has been briefly described above. Further, details of the present disclosure can be clarified by reading a mode (hereinafter, referred to as “embodiment”) for carrying out the disclosure to be described below with reference to the accompanying drawings.

DESCRIPTION OF EMBODIMENTS

A specific embodiment according to the present disclosure will be described below with reference to the drawings.

<Basic Configuration of Onboard Connection System>

FIG.1is a block diagram illustrating an onboard connection system100having a basic configuration.

A vehicle equipped with the onboard connection system100illustrated inFIG.1has a plurality of regions A1, A2, A3, and A4that are partitioned in advance. As a specific example, the regions A1to A4are respectively assigned to a region at the right half and a region at the left half of the vehicle, a region near an instrument panel, a region near a luggage compartment, a region in an engine room, and the like.

On the other hand, a large number of onboard devices having various functions, that is, a large number of electrical components20as auxiliary devices are provided in various portions on the vehicle. Various sensors, cameras, actuators, lighting devices, and the like are generally included in these electrical components20.

In the configuration illustrated inFIG.1, one zone ECU10is disposed inside each of the regions A1to A4of the vehicle. The zone ECU10disposed in the region A1is configured to have a function of controlling all the electrical components20disposed in the region A1. Similarly, the zone ECU10disposed in the region A2is configured to have a function of controlling all the electrical components20disposed in the region A2. The zone ECU10disposed in the region A3have a function of controlling all the electrical components20disposed in the region A3. The zone ECU10disposed in the region A4is configured to have a function of controlling all the electrical components20disposed in the region A4.

Further, the onboard connection system100includes a central ECU30. The central ECU30has a function of integrally managing control of the zone ECUs10and the electrical components20disposed in all the regions A1to A4on the vehicle. Further, conceptually, the function of the central ECU30is assumed to correspond to a function corresponding to a human brain, that is, a function of performing an upper-level process such as “recognition”, “determination”, and “instruction”.

On the other hand, conceptually, the zone ECU10disposed in each of the regions A1to A4has a function required for controlling a portion corresponding to a human limb in each region, that is, a function such as “detection”, “report”, and “operation according to an instruction”.

Therefore, the zone ECUs10disposed in the regions A1to A4and the central ECU30are connected by independent signal paths43so that signals and information can be transmitted via the signal paths43.

Further, a downstream side of the zone ECU10in the region A1is connected to the various electrical components20disposed in the region A1via signal paths44. Similarly, the downstream side of the zone ECU10in the region A2is connected to the various electrical components20disposed in the region A2via the signal paths44. The downstream side of the zone ECU10in the region A3is connected to the various electrical components20disposed in the region A3via the signal paths44. The downstream side of the zone ECU10in the region A4is connected to the various electrical components20disposed in the region A4via the signal paths44.

On the other hand, electric circuits inside the zone ECUs10and the electrical components20in the regions A1to A4, and inside the central ECU30require a supply of power supply electric power. Therefore, an output of an onboard battery35is electrically connected to power supply input terminals of the zone ECUs10in the regions A1to A4via independent power supply paths41. Further, the output of the onboard battery35is electrically connected to a power supply input terminal of the central ECU30via a power supply path42.

Further, a terminal on the downstream side of the zone ECU10disposed in the region A1is electrically connected to power supply input terminals of the electrical components20in the region A1via power supply paths45. Similarly, the terminal on the downstream side of the zone ECU10disposed in the region A2is electrically connected to the power supply input terminals of the electrical components20in the region A2via the power supply paths45. The terminal on the downstream side of the zone ECU10disposed in the region A3is electrically connected to the power supply input terminals of the electrical components20in the region A3via the power supply paths45. The terminal on the downstream side of the zone ECU10disposed in the region A4is electrically connected to the power supply input terminals of the electrical components20in the region A4via the power supply paths45.

Therefore, a wire harness WH, which is used for achieving the onboard connection system100ofFIG.1, needs to be provided with a large number of electric wires for individually and electrically connecting the power supply paths41, the power supply path42, the signal paths43, and the signal paths44and the power supply paths45in each of the regions A1to A4. In addition, regarding the electric wire used for each of the power supply paths41,42, and45, it is necessary to adopt a relatively thick electric wire in consideration of the magnitude of a power supply current required for a corresponding load and a wiring length.

FIG.2is a block diagram illustrating an onboard connection system100A in which a part of the basic configuration illustrated inFIG.1is modified.FIG.3is a block diagram illustrating an overview of a signal connection system in the onboard connection system100A ofFIG.2.FIG.4is a block diagram illustrating an overview of a power supply connection system in the onboard connection system100A ofFIG.2.

In the configuration illustrated inFIGS.2to4, regarding a partition in a case in which a large number of electrical components20are individually managed, in addition to differences in the regions A1to A4in which the electrical components20are disposed, two function groups G1and G2independent of the regions A1to A4are assigned for specific functions.

For example, even when the electrical components20belonging to the function group G1are disposed in the region A2, the electrical components20are managed as the function group G1without relation to the partition of the region A2. Further, for example, even when the electrical components20belonging to the function group G2are disposed in the region A3, the electrical components20are managed as the function group G2without relation to the partition of the region A3.

As a specific example, the electrical components20each having a function of advanced driver-assistance systems (ADAS) are prioritized in management as the function group G1without relation to the regions A1to A4in which the electrical components20are disposed. In addition, the electrical components20each having a function of a human machine interface (HMI) are prioritized in management as the function group G2without relation to the regions A1to A4in which the electrical components20are disposed.

Therefore, in addition to the zone ECUs10, the onboard connection system100A includes an independent ECU11having a function of controlling the electrical components20of the function group G1, and an independent ECU12having a function of controlling the electrical components20of the function group G2.

As illustrated inFIG.2, a downstream side of the independent ECU11is connected to the electrical components20belonging to the function group G1via signal paths44A. Further, a downstream side of the independent ECU12is connected to the electrical component20belonging to the function group G2via the signal paths44A.

In addition, the central ECU30is connected to the independent ECUs11and12via signal paths48so that the central ECU30can individually manage the independent ECUs11and12.

Further, a power supply input terminal of the independent ECU11is electrically connected to the onboard battery35via a power supply path46, and a power supply input terminal of the independent ECU12is electrically connected to the onboard battery35via a power supply path47.

Further, the power supply input terminal of each electrical component20belonging to the function group G1is connected to, via a power supply path51, the downstream side of the zone ECU10that manages the region in which the electrical component20is disposed. Similarly, the power supply input terminal of each electrical component20belonging to the function group G2is connected to, via a power supply path52, the downstream side of the zone ECU10that manages the region in which the electrical component20is disposed.

Therefore, in addition to elements of the wire harness WH illustrated inFIG.1, a wire harness WH1, which is necessary for achieving the onboard connection system100A illustrated inFIG.2, needs to further include the power supply paths46and47, the signal paths48and44A, and the power supply paths51and52.

The signal paths in the onboard connection system100A ofFIG.2are connected as illustrated inFIG.3. That is, the central ECU30is connected to zone ECUs10A in the regions A1to A4via the signal paths43, and the central ECU30is connected to the independent ECUs11and12via the signal paths48. Further, in each of the regions A1to A4, the zone ECU10A is connected to the electrical components20in the region via the signal paths44. In addition, the electrical components20belonging to the function groups G1and G2are connected to the independent ECUs11and12via the signal paths44A without relation to the regions A1to A4in a corresponding manner.

Therefore, each zone ECU10A can control the electrical components20connected to the downstream side via the signal paths44or can input signals from the electrical components20. Further, each of the independent ECUs11and12can control the electrical components20connected to the downstream side thereof via the signal paths44A or can input the signals from the electrical components20.

In addition, the central ECU30can input and output signals to and from the zone ECUs10A in the regions A1to A4via the signal paths43, and can manage the zone ECUs10A and the electrical components20under the control of the zone ECUs10A. Further, the central ECU30can input and output signals to and from the independent ECUs11and12of the function groups G1and G2via the signal paths48, and can manage the independent ECUs11and12of the function groups G1and G2and the electrical components20under the control of the independent ECUs11and12.

On the other hand, the power supply paths in the onboard connection system100A are connected as illustrated inFIG.4. The power supply electric power is supplied from the onboard battery35to the central ECU30via the power supply path42. Further, the power supply electric power is supplied from the onboard battery35to the zone ECUs10A in the regions A1to A4via the power supply paths41. Further, the power supply electric power is supplied from the onboard battery35to the independent ECUs11and12via the power supply paths46and47.

Further, the power supply electric power is supplied to the electrical components20in each of the regions A1to A4via the power supply paths45. Further, the power supply electric power is supplied to the power supply input terminals of the electrical components20belonging to the function groups G1and G2from outputs of the zone ECUs10A managing the same regions via the power supply paths51and52.

In the case of the configuration of the onboard connection system100A illustrated inFIGS.2to4, a large number of electrical components20are particularly connected to the downstream side of the zone ECU10A in each of the regions A1to A4, and thus even when the independent ECUs11and12are provided, there is a concern that the zone ECUs10A increase in size as the electrical components20increase in size. That is, since an internal circuit of each zone ECU10A increases or the number of terminals of a connector increases, the size of a housing for the zone ECU10A increases. In addition, the number of electric wires (the total number of electric wires for the power supply paths45,51, and52) included in the wire harness connecting the zone ECU10A and the electrical components20in each of the regions A1to A4increases, and the outer size of the wire harness increases.

DESCRIPTION OF EMBODIMENT

A specific embodiment according to the present disclosure will be described below with reference to the drawings.

FIG.5is a block diagram illustrating an overview of a power supply connection system in an onboard connection system100B according to an embodiment of the present disclosure.FIG.6is a block diagram illustrating a detailed configuration example of the onboard connection system100B as that ofFIG.5. A configuration of a signal connection system of the onboard connection system100B is the same as that of the onboard connection system100A illustrated inFIG.2.

As illustrated inFIG.6, the onboard connection system100B includes the zone ECUs10A disposed in the regions A1to A4, the independent ECU11that controls the electrical components20in the function group G1, the independent ECU12that controls the electrical component20in the function group G2, and the central ECU30that integrally manages all the above.

The electrical components20disposed in the region A1on the vehicle are connected to the downstream side of the zone ECU10A disposed in the region A1via a wire harness including the signal paths44and the power supply paths45.

Similarly, the electrical components20disposed in the region A2on the vehicle are connected to the downstream side of the zone ECU10A disposed in the region A2via the wire harness including the signal paths44and the power supply paths45. The electrical components20disposed in the region A3on the vehicle are connected to the downstream side of the zone ECU10A disposed in the region A3via the wire harness including the signal paths44and the power supply paths45. The electrical components20disposed in the region A4on the vehicle are connected to the downstream side of the zone ECU10A disposed in the region A4via the wire harness including the signal paths44and the power supply paths45.

In the example ofFIG.6, the zone ECU10A in the region A1includes a control function corresponding to a limb of a system A and a control function corresponding to a limb of a system B. In addition, the zone ECU10A in the region A2includes the control function corresponding to the limb of the system A, the control function corresponding to the limb of the system B, and a control function corresponding to a limb of a system C. The zone ECU10A in the region A3includes the control function corresponding to the limb of the system A and a control function corresponding to a limb of a system N. The zone ECU10A in the region A4includes the control function corresponding to the limb of the system C.

On the other hand, the electrical components20included in the function group G1are controlled by the independent ECU11without relation to the partition of the regions A1to A4in which the electrical components20are disposed. Further, the electrical components20included in the function group G1are connected to the downstream side of the independent ECU11via the wire harness including the signal paths44A and power supply paths51A.

In addition, the electrical components20included in the function group G2are controlled by the independent ECU12without relation to the partition of the regions A1to A4in which the electrical components20are disposed. Further, the electrical components20included in the function group G2are connected to the downstream side of the independent ECU12via the wire harness including the signal paths44A and power supply paths52A.

In the example ofFIG.6, the independent ECU11includes a control function corresponding to a brain of an ADAS system and a control function corresponding to a limb of the ADAS system. Further, the independent ECU12includes a control function corresponding to a brain of an HMI system and a control function corresponding to a limb of the HMI system.

The central ECU30is provided with control functions corresponding to respective brains of the system A, the system B, the system C, . . . , and the system N.

The central ECU30is connected to the zone ECUs10A in the regions A1to A3via the wire harness including signal paths43-1,43-2, and43-3(the signal paths43). Further, the independent ECUs11and12are connected to the central ECU30via the wire harness including the signal paths48.

Each of the signal paths43and48is implemented by a signal line that allows transmission of a simple signal, a controller area network (CAN), a local interconnect network (LIN), or a communication line that allows signal transmission through a multiplex communication network such as Ethernet (registered trademark).

Therefore, the central ECU30can manage the zone ECUs10A in the regions A1to A3or can share information and the like with the independent ECUs11and12.

On the other hand, power supply input terminals of the zone ECUs10A in the regions A1to A4are connected to the output of the onboard battery35via the independent power supply paths41. In addition, the power supply input terminals of the central ECU30and the independent ECUs11and12are connected to the output of the onboard battery35via the power supply paths42,46, and47, respectively.

Therefore, control units of the zone ECUs10A in the regions A1to A4, the independent ECUs11and12, and the central ECU30can operate by the power supply electric power supplied from the onboard battery35.

As illustrated inFIG.5, among the electrical components20disposed in each of the regions A1to A4, the electrical components20not belonging to the function groups G1and G2are connected to the downstream side of the zone ECU10A via the power supply paths45. Therefore, these electrical components20can operate by the power supply electric power supplied from the zone ECU10A in the same region.

On the other hand, the electrical components20belonging to the function group G1are connected to an output of the independent ECU11via the power supply paths51A without relation to the partition of the regions A1to A4in which the electrical components20are disposed. In addition, the electrical components20belonging to the function group G2are connected to an output of the independent ECU12via the power supply paths52A without relation to the partition of the regions A1to A4in which the electrical components20are disposed.

The electrical components20of the function group G1can operate by the power supply electric power supplied from the output of the independent ECU11. In addition, the electrical components20of the function group G2can operate by the power supply electric power supplied from the output of the independent ECU12.

Further, the electrical components20other than the electrical components20of the function groups G1and G2can operate by the power supply electric power supplied from the zone ECU10A disposed in the same partitioned region among the regions A1to A4in which the electrical components20are disposed.

That is, in the onboard connection system100B ofFIG.5, routing paths of the power supply paths51A and52A are significantly different from those of the power supply paths51and52of the onboard connection system100A ofFIG.4. Due to this difference in the configuration, when the total number and types of the electrical components20increase, the miniaturization of the zone ECUs10A in the regions A1to A4and the reduction in diameter of the wire harness connected to the downstream sides of the zone ECUs10A are facilitated.

FIG.7is a flowchart illustrating processing procedures of an onboard system design method according to the embodiment of the present disclosure. By designing the wire harness according to the processing procedures illustrated inFIG.7, it is possible to relatively easily design a wire harness having an appropriate configuration that can be used in the onboard connection system100B illustrated inFIGS.5and6.

In the example illustrated inFIG.7, it is assumed that a designer performs design work while performing various input operations by using a computer system including a design assistance system200. Such a design assistance system200can assist the design work by the designer based on information such as data such as shapes and sizes of respective parts of the vehicle provided with the wire harness, positions at which the various electrical components provided on the vehicle are provided, and various specifications for the electrical components. There is also a possibility that a computer of the design assistance system200can automate the design work performed by the designer.

The processing procedures inFIG.7will be described below. An order of executing processes illustrated inFIG.7can be changed as necessary.

The designer operates the design assistance system200to determine a plurality of regions partitioned on a target vehicle in S11. Therefore, for example, each of the regions A1to A4inFIGS.1and6is determined. Specifically, the region on the right side and the region on the left side of the vehicle, the region near the instrument panel, the region near the luggage compartment, the region in the engine room, and the like are specified. In the example ofFIG.7, information on the plurality of regions determined in S11is held in a data holding unit DB1as a part of primary design data.

In S12, the designer operates the design assistance system200to determine the zone ECUs10disposed in the regions determined in S11. For example, as in the onboard connection system100illustrated inFIG.1, one zone ECU10is disposed in a range of each of the regions A1to A4. In the example ofFIG.7, information on the zone ECUs10in the regions determined in S12is held in the data holding unit DB1as a part of the primary design data.

The designer operates the design assistance system200to determine the disposition of the central ECU30in S13. In the example ofFIG.7, information on the disposition of the central ECU30determined in S13is held in the data holding unit DB1as a part of the primary design data.

The designer operates the design assistance system200to determine a basic routing path of the wire harness in S14. For example, regarding the wire harness including the power supply paths41and42and the signal paths43illustrated inFIG.1, connection positions at both ends, an electric wire length, a path to be passed, and the like are determined for each electric wire. In the example ofFIG.7, information on the basic routing path determined in S14is held in the data holding unit DB1as a part of the primary design data.

In S15, the designer operates the design assistance system200to determine a routing path of a “first connection circuit” necessary for connecting the electrical components20to the downstream side of the zone ECU10in each of the regions A1to A4in a wire harness configuration. For example, the signal paths44and the power supply paths45in each of the regions A1to A4illustrated inFIG.1correspond to the first connection circuit. In the example ofFIG.7, information on the routing path of the first connection circuit determined in S15is held in the data holding unit DB1as a part of the primary design data.

For example, in order to improve the configuration of the onboard connection system100illustrated inFIG.1, the designer operates the design assistance system200to selectively extract, from the primary design data, an independent function from each of the regions A1to A4in S16. As a representative example, it is assumed that the electrical components20each having the function of the advanced driver-assistance systems (ADAS) are extracted as the function group G1from all the regions A1to A4, and the electrical components20each having the function of the human machine interface (HMI) are extracted as the function group G2from all the regions A1to A4.

In S17, the designer operates the design assistance system200to determine the disposition of the independent ECUs11and12that control the independent functions extracted in S16. In the example ofFIG.7, information on the disposition of the independent ECUs11and12determined in S16is held in a data holding unit DB2as a part of secondary design data.

In S18, the designer operates the design assistance system200to transfer power supply connection paths of the independent functions extracted in S16in the “first connection circuit” included in the wire harness of the primary design data in the data holding unit DB1from the zone ECUs10in the primary design data to the independent ECUs11and12in the secondary design data. Accordingly, for example, the routing paths of the power supply paths51and52in the “first connection circuit” illustrated inFIG.4are changed to those of the power supply paths51A and52A illustrated inFIG.5.

As a result of the process in S18, the secondary design data is generated from the primary design data in the data holding unit DB1and is held in the data holding unit DB2. Accordingly, data representing a configuration of the wire harness (the wire harness in the onboard connection system100B ofFIGS.5and6), which is obtained after a part of the routing paths of the “first connection circuit” in the configuration of the wire harness in the primary design data is changed, is obtained.

In order to optimize the configuration of the wire harness by reflecting a result of transferring the power supply connection paths in S18, the designer operates the design assistance system200to generate optimized tertiary design data from the secondary design data in the data holding unit DB2in S19.

For example, since the power supply paths51and52inFIG.4are changed to the power supply paths51A and52A inFIG.5by the transferring in S18, the power supply paths51and52, which become unnecessary on the downstream sides of the zones ECU10A, are deleted from the configuration of the wire harness in S19. In addition, since unnecessary portions are generated in the internal circuits of the zone ECUs10A and terminals of wire harness connecting connectors due to the deletion of the power supply paths51and52, the number of terminals of the connectors is reduced, or each connector itself is replaced with a small component. In addition, an unnecessary circuit in each zone ECU10A is deleted to miniaturize the zone ECU10A. In addition, since the number of remaining electric wires of the wire harness after the power supply paths51and52are deleted is reduced, the configuration can be changed to a further optimum state by changing a routing path or a branch position of the wire harness or shortening the electric wire length. Further, it is also conceivable to change a specification of an exterior material of the wire harness.

The generated tertiary design data is held in a data holding unit DB3. Based on the tertiary design data, a wire harness having an appropriate configuration that can be adopted in the onboard connection system100B illustrated inFIGS.5and6can be manufactured.

FIG.8is a block diagram illustrating a modification of the onboard connection system100B ofFIG.6.FIG.9is a block diagram illustrating an overview of a signal connection system in an onboard connection system100C ofFIG.8.FIG.10is a block diagram illustrating an overview of a power supply connection system in the onboard connection system100C ofFIG.8.

The onboard connection system100C illustrated inFIGS.8to10includes an external power supply box60in addition to the zone ECUs10A, the central ECU30, the independent ECUs11and12described above. The added external power supply box60is provided with, as large current control units61and62, functions for a supply of the power supply electric power to a load consuming a large current and control corresponding to a limb.

In the example illustrated inFIGS.8to10, a supply of the power supply electric power to a part of loads each consuming a large current in the electrical components20included in the function group G1or G2is configured to be performed by the external power supply box60instead of the independent ECUs11and12.

When a power supply circuit handles a large current, a space required for disposing the power supply circuit is increased, and a heat generation measure and a noise measure are also required. Therefore, when the loads consuming a large current are connected to the independent ECUs11and12, a burden on each of the independent ECUs11and12may increase.

Therefore, in the onboard connection system100C illustrated inFIGS.8to10, in order to reduce the burden on each of the independent ECUs11and12, the external power supply box60disposed outside the independent ECUs11and12is used.

A power supply input terminal of the external power supply box60is connected to the output of the onboard battery35via a power supply path63. In addition, the external power supply box60is connected to the independent ECU11via a signal path66, and the external power supply box60is connected to the independent ECU12via a signal path65.

In addition, in the example illustrated inFIG.8, actuators (a part of the loads in the electrical components20) each consuming a large current in the function group G1are connected to an output of the external power supply box60via power supply paths64.

Therefore, even when a part of the electrical components20in the function group G1consumes a large current, no large current flows through an internal circuit of the independent ECU11, and the burden on the independent ECU11can be reduced.

FIG.11is a block diagram illustrating a modification of the signal connection system of the onboard connection system illustrated inFIG.9.FIG.12is a block diagram illustrating a specific onboard connection system100D including the signal connection system illustrated inFIG.11.

In the configuration illustrated inFIG.9, all the electrical components20disposed in each of the regions A1to A4are connected to the downstream side of the zone ECU10A disposed in the same region via the wire harness. On the other hand, in the onboard connection system100D illustrated inFIGS.11and12, only signals of switches among a large number of electrical components20disposed in the regions A1to A4are connected to the downstream side of the independent ECU12via the wire harness including signal paths44B.

Further, in the example ofFIG.12, only signals of switches among the electrical components20included in the function group G1are connected to the downstream side of the independent ECU12via the wire harness including signal paths44C.

In the configuration illustrated inFIG.12, the signals of a large number of switches disposed in various places on the vehicle can be intensively monitored by the independent ECU12. The independent ECU12can read the signals of a large number of switches and can transmit information indicating a state of each switch to the central ECU30via the signal path48. The central ECU30can notify the zone ECUs10A in the regions A1to A4and the independent ECU11of the information indicating the state of each switch received from the independent ECU12.

FIG.13is a block diagram illustrating a modification of the onboard connection system illustrated inFIG.8.

An onboard connection system100E illustrated inFIG.13further includes an external power supply box70in addition to the zone ECUs10A, the central ECU30, the independent ECUs11and12, and the external power supply box60illustrated inFIG.8. The added external power supply box70includes a plurality of large current power supply circuits71that supply the power supply electric power to loads each consuming a large current among the electrical components20disposed in the regions A1to A4.

As illustrated inFIG.13, a power supply input terminal of the external power supply box70is connected to the onboard battery35via a power supply path72. Further, the external power supply box70is connected to the zone ECU10A via a signal path74. Further, a large current actuator81in the region A1, a large current lamp82in the region A2, and a large current actuator83in the region A3are connected to a downstream side of the external power supply box70via the wire harness including independent power supply paths73.

Therefore, even when the loads (81to83) each consuming a large current are included in the electrical components20disposed in the regions A1to A4, no large current flows through the internal circuits of the zone ECUs10A disposed in the regions A1to A4. Accordingly, regarding the zone ECUs10A, it is possible to reduce burdens such as a space required for disposing a large-sized power supply circuit, the heat generation measure, and the noise measure. In addition, it is easy to miniaturize the connector of each zone ECU10A.

FIG.14is a block diagram illustrating a modification at the vicinity of the zone ECU included in the onboard connection system.

For example, in a case in which the electrical components20controlled by the zone ECU10A in any one of the regions refer to a rear combination lamp disposed on the rear side of the vehicle, it is assumed that the configuration illustrated inFIG.14is adopted.

In the configuration illustrated inFIG.14, a function corresponding to the zone ECU10A described above is achieved by a combination of a zone ECU10B and a small-scale electronic unit10C. The small-scale electronic unit10C illustrated inFIG.14implements a part of the function included in the zone ECU10A.

The zone ECU10B has a configuration in which the implementation of the function of the small-scale electronic unit10C as a part of the function included in the zone ECU10A is omitted. Therefore, the zone ECU10B is easily miniaturized as compared with the zone ECU10A.

The central ECU30illustrated inFIG.14includes a power supply connector CN11and a signal connector CN12. Further, the zone ECU10B includes a connector CN21on an upstream side and a connector CN22on a downstream side. Further, the small-scale electronic unit10C includes a connector CN31on an upstream side, a connector CN32on a downstream side, and a joint connector CN33.

The connector CN11of the central ECU30is connected to the onboard battery35via the power supply path42. Further, the connector CN12of the central ECU30is connected to the connector CN21of the zone ECU10B via the signal path43. Regarding the signal path43, for example, a communication line capable of performing multiplex data communication such as Ethernet is adopted. Further, the connector CN21and the onboard battery35are connected via the power supply path41.

In the example ofFIG.14, the connector CN22of the zone ECU10B is connected to the connector CN31of the small-scale electronic unit10C via a wire harness WH2. The wire harness WH2includes, for example, a signal line capable of performing multiplex data communication such as a LIN, a power supply line, and a ground (GND) line.

By performing signal transmission between the zone ECU10B and the small-scale electronic unit10C in the multiplex data communication, the number of signal lines included in the wire harness WH2can be reduced. Further, by reducing a function implemented in the zone ECU10B as compared with the zone ECU10A, it is easy to reduce a diameter of the wire harness WH2.

A wire harness WH3connected to the connector CN32and the joint connector CN33on the downstream side of the small-scale electronic unit10C connects the small-scale electronic unit10C to the electrical components20such as a brake lamp, a back lamp, and a winker lamp, which are loads. The wire harness WH3includes an independent power supply line, a ground line, and a signal line for each load.

In the example ofFIG.14, the small-scale electronic unit10C implements the control functions of the system A, the system B, the system C, and the like, and thus these functions are not required to be implemented in the zone ECU10B. It is assumed that, for example, a function corresponding to a limb for controlling the electrical components20such as a power window and a door locking mechanism in the same region is implemented inside the zone ECU10B.

FIG.15is a block diagram illustrating specific examples of functions of units included in an onboard connection system.

In the example ofFIG.15, a configuration of an onboard connection system100F including the zone ECU10A disposed in a region near a door of the vehicle is illustrated.

The zone ECU10A inFIG.15includes an ECU control circuit and a door power supply circuit. Further, the independent ECU11inFIG.15has a control function of the advanced driver-assistance systems (ADAS), and includes a camera power supply circuit and an air bag circuit in addition to an ECU control circuit. Further, the independent ECU12inFIG.15has control functions of the human machine interface (HMI) and a multimedia (MM), and includes an audio circuit and a switch circuit in addition to an ECU control circuit.

The connector CN21on the upstream side of the zone ECU10A, a connector CN41on an upstream side of the independent ECU11, and a connector CN51on an upstream side of the independent ECU12are connected to a wire harness95on an instrument panel side. The wire harness95includes an independent power supply line for each system connected to the onboard battery35.

Further, the wire harness95also includes a plurality of independent signal lines for each system. That is, a signal line connecting the connector CN21of the zone ECU10A and the connector CN12of the central ECU30, a signal line connecting the connector CN41of the independent ECU11and a connector CN13of the central ECU30, and a signal line connecting the connector CN51of the independent ECU12and a connector CN14of the central ECU30are included in the wire harness95.

In addition, the connector CN22on the downstream side of the zone ECU10A is connected to wire harnesses91and92. The wire harness91is connected to a ground circuit, and the wire harness92is connected to the electrical components20such as the power window and the door locking mechanism inside the door. The wire harness92includes a plurality of independent power supply lines and a plurality of signal lines for each electrical component20.

A connector CN42on the downstream side of the independent ECU11is connected to the electrical components20such as a camera and an air bag belonging to the advanced driver-assistance systems via a wire harness93. The wire harness93includes a plurality of independent power supply lines and a plurality of signal lines for each electrical component20.

A connector CN52on the downstream side of the independent ECU12is connected to the electrical components20such as an audio device and a door master switch belonging to the human machine interface or the multimedia via a wire harness94. The wire harness94includes a plurality of independent power supply lines and a plurality of signal lines for each electrical component20.

In the onboard connection system100F illustrated inFIG.15, even when the electrical components20such as the air bag and the camera are included in the region near the door in which the zone ECU10A is disposed, the zone ECU10A does not need to supply the power supply electric power to these electrical components20. That is, a path for supplying the power supply electric power to the electrical components20such as the air bag and the camera is transferred to the wire harness93on the downstream side of the independent ECU11. Therefore, the number of power supply lines included in the wire harness92can be reduced, and a diameter of the wire harness92can be reduced.

In addition, since functions of the camera power supply circuit and the air bag circuit are provided on the independent ECU11, even when the electrical components20such as the camera and the air bag are in the same region as the zone ECU10A, control functions thereof are not required to be implemented in the zone ECU10A. Therefore, an implementation circuit of the zone ECU10A can be removed, and the zone ECU10A can be miniaturized. In addition, the number of terminals of the connector CN22can be reduced, and the connector CN22can be miniaturized.

Characteristic matters regarding the above onboard connection system and the onboard system design method are briefly summarized in the following [1] to [5]. [1] An onboard connection system (100B) includes:at least one zone ECU (10A) disposed in one of partitioned regions (A1to A4) on a vehicle and configured to control a first device (the electrical components20) disposed in the same region;at least one independent ECU (11,12) configured to control a second device (the electrical components20in the function group G1or G2) independent of the control performed by the zone ECU without relation to the partition of the region in which the first device is disposed, the second device being disposed in one of the regions;a central ECU (30) configured to manage the zone ECU and the independent ECU;a first power supply connection path (the power supply paths41and42) that connects an onboard power supply (the onboard battery35) and power supply inputs of the zone ECU and the central ECU; anda second power supply connection path (the power supply paths46and47) that is a path independent of the first power supply connection path and connects the onboard power supply and a power supply input of the independent ECU, in whichpower supply electric power to the second device is supplied from the independent ECU (via the power supply paths51A and52A).

According to the onboard connection system having the configuration described in the above [1], it is possible to reduce the diameter of the wire harness required for connecting the zone ECU disposed in each region and the first device disposed in the same region. That is, regarding the second device independent of the control performed by the zone ECU, even when the second device is the first device disposed in the same region as the zone ECU, it is not necessary to supply the power supply electric power from the zone ECU, and thus the number of power supply paths in the wire harness connected to the downstream side of the zone ECU can be reduced. In addition, it is also possible to remove the power supply circuit inside the zone ECU and miniaturize the connector.

[2] The onboard connection system (100C) according to the above [1] further includes:a power supply box (the external power supply box60) having a power supply electric power supply function with respect to a large current load consuming a large current in the second device;a third power supply connection path (the power supply path63) that is a path independent of the first power supply connection path and the second power supply connection path, and that connects the onboard power supply and a power supply input of the power supply box;a fourth power supply connection path (the power supply paths64) that connects a power supply output of the power supply box and the large current load; anda signal connection path (the signal paths65and66) that connects a control signal of the independent ECU to the power supply box.

According to the onboard connection system having the configuration described in the above [2], it is not necessary to provide a power supply circuit through which a large current flows inside the independent ECU. Therefore, it is not necessary to secure the space for disposing the large-sized power supply circuit inside the independent ECU, and a special heat generation measure and a special noise measure are also unnecessary. Further, it is also easy to miniaturize the connector inside the independent ECU.

[3] The onboard connection system (100D) according to the above [1] or [2] further includes:a switch signal connection path (the signal paths44B) that connects a signal of at least a part of switches included in the first device and a signal input of the independent ECU.

According to the onboard connection system having the configuration described in the above [3], it is easy to intensively manage information on a large number of switches disposed in various regions by the independent ECU. In addition, it is easy to reduce the number of signal lines included in the wire harness connected to the downstream sides of the zone ECUs in the regions and reduce the diameter of the wire harness.

[4] The onboard connection system according to any one of the above [1] to [3] further includes:a second power supply box (the external power supply box70) having a power supply electric power supply function with respect to a second large current load consuming a large current in the first device;a fifth power supply connection path (the power supply path72) that is a path independent of the first power supply connection path and the second power supply connection path, and that connects the onboard power supply and a power supply input of the second power supply box; anda sixth power supply connection path (the power supply paths73) that connects a power supply output of the second power supply box and the second large current load.

According to the onboard connection system having the configuration described in the above [4], it is not necessary to provide a power supply circuit through which a large current flows inside the zone ECU in each region. Therefore, it is not necessary to secure the space for disposing the large-sized power supply circuit inside the zone ECU, and a special heat generation measure and a special noise measure are also unnecessary. Further, it is also easy to miniaturize the connector inside the zone ECU.

[5] An onboard system design method includes:a procedure (S11) for determining a plurality of regions (A1to A4) formed by partitioning a space on a vehicle;a procedure (S12) for determining, regarding each of the regions, disposition of zoneECUs (10A) each of which controls all devices (the electrical components20) disposed in the corresponding region as control targets;a procedure (S13) for determining disposition of a central ECU (30) having a function of integrally managing a plurality of the zone ECUs;a procedure (S15) for determining, regarding each of the plurality of regions, a routing path of a first connection circuit that connects each of all the devices disposed in the corresponding region to the corresponding zone ECU;a procedure (S16) for selectively extracting, as an independent function, a function separable from the control targets of the zone ECU among the devices (the electrical components20) in each of the plurality of regions;a procedure (S17) for determining an independent ECU that controls the independent function as a control target;a procedure (S18) for separating a power supply connection path at a portion corresponding to the independent function assigned to the independent ECU in the first connection circuit from the zone ECU and transferring the power supply connection path to the independent ECU; and a procedure (S19) for reflecting a situation after the transferring of the power supply connection path and optimizing a configuration of a power supply connection circuit in at least a part of a wire harness.

By applying the onboard system design method described in the above [5] and performing designs of the wire harness and the like, it is easy to perform design work of a system configuration useful for miniaturizing the zone ECU and reducing the diameter of the wire harness for each part. For example, it is easy to design the onboard connection system100B having the configuration illustrated inFIG.6from the state of the configuration illustrated inFIG.1through the state of the configuration illustrated inFIG.2.

Note that, the present disclosure is not limited to the embodiment described above and can be appropriately modified, improved, and the like. In addition, materials, shapes, sizes, numbers, disposition positions and the like of components in the embodiment described above are freely selected and are not limited as long as the present disclosure can be implemented.

Note that the present application is based on a Japanese Patent Application (No. 2022-031889) filed on Mar. 2, 2022, the contents of which are incorporated herein by reference.

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