Sensor and sensor system

Abstract

The present invention provides a sensor and a sensor system. The hydrogen sensors (51 to 54) have communication terminals, a plurality of identification terminals, and ID setting units (51s to 54s). The communication terminals are connected to the first communication bus (CAN1) or the second communication bus (CAN2) and communicate with the vehicle ECU (36). The plurality of identification terminals are set to any one of an open state (OPEN) in which they are not connected to any potential and a ground state (GND) in which they are connected to the ground potential. The ID setting units (51s to 54s) set an identifier in either a standard format or an extended format according to the different communication buses to which the communication terminals are connected. Accordingly, even if the number of sensors for which identifiers are set is increased, confusion of the identifiers can be prevented.

Description

Technical Field

[0001] The present invention relates to a sensor and a sensor system. Background Art

[0002] In the prior art, a method for setting a sensor identifier is known. A plurality of external terminals for setting an identifier are provided on a sensor, and the identifier of the sensor is set (assigned) by a combination of voltage levels of the external terminals.

[0003] For example, in the method for setting an identifier of an in-vehicle sensor disclosed in Japanese Patent Application Laid-Open No. 2015-136989, the state in which the external terminal of the in-vehicle sensor is connected to the ground potential (GND) is recognized as a low level. The state in which the potential of the external terminal is equal to the control power supply voltage inside the sensor is recognized as a high level. In the case where a failure occurs in one external terminal due to disconnection or the like (in the case of a 1-bit failure), the identifier of the in-vehicle sensor with the failure may be the same as the identifier of a normal in-vehicle sensor. Therefore, in Japanese Patent Application Laid-Open No. 2015-136989, for a combination with a 1-bit level inversion, no identifier is assigned (paragraphs

[0042] and

[0047] of Japanese Patent Application Laid-Open No. 2015-136989). Summary of the Invention

[0004] According to the identifier setting method of Japanese Patent Application Laid-Open No. 2015-136989 as described above, it is possible to prevent the identifier of the in-vehicle sensor with a failure from being confused with the identifier of a normal in-vehicle sensor on the communication bus. In addition, the identifier assigned to the failed in-vehicle sensor is not used on the communication bus. Therefore, the possibility of determining the in-vehicle sensor with a failure is increased.

[0005] However, in the identifier setting method of Japanese Patent Application Laid-Open No. 2015-136989, there is a problem that the number of sensors for which an identifier can be set is small. For example, when a sensor having two external terminals is connected to a vehicle ECU, identifiers can be set for two sensors. The maximum number of sensors for which an identifier can be set is half of the square of the number of external terminals. When three or more sensors are connected to the vehicle ECU, the vehicle ECU cannot determine the sensor with a failure. If a sensor with a large number of external terminals is used to prevent identifier duplication, the installation space of the connector increases. As a result, the cost increases.

[0006] An object of the present invention is to solve the above technical problems.

[0007] The method of the present invention is a sensor that is connected to a control device through any one of two communication buses built on a moving body and is identified by an inherent identifier. The sensor has a communication terminal, a plurality of identification terminals, and an identifier setting unit. Among them, the communication terminal is connected to one of the two communication buses or the other communication bus to communicate with the control device; a plurality of the identification terminals are set to be in either an open state where they are not connected to any potential or a grounded state where they are connected to the ground potential; the identifier setting unit sets the identifier of the sensor according to the connection state of the plurality of identification terminals and the difference in the communication bus to which the communication terminal is connected. The identifier setting unit sets the identifier in different modes according to whether the communication bus connected to the communication terminal is the one communication bus or the other communication bus.

[0008] According to the present invention, even if the number of sensors for setting identifiers is increased, confusion of identifiers can be prevented.

[0009] According to the following description of the embodiments with reference to the drawings, the above objects, features, and advantages should be easily understood. Description of the Drawings

[0010] Figure 1A It is a side view showing the schematic structure of a fuel cell vehicle equipped with the sensor system according to the present embodiment. Figure 1B It is a top view showing the schematic structure of a fuel cell vehicle.

[0011] Figure 2 It is a circuit block diagram of the sensor system.

[0012] Figure 3 It is a schematic physical wiring diagram of a hydrogen sensor, a vehicle ECU, and a vehicle wiring harness having a trunk line and branch line components.

[0013] Figure 4 It is an explanatory diagram showing the relationship between the identification terminals of the hydrogen sensor, the communication bus, and the identifier set for the hydrogen sensor.

[0014] Figure 5 It is a schematic flowchart showing the process of installing the hydrogen sensor on the vehicle wiring harness.

[0015] Figure 6 It is a circuit block diagram of the sensor system in the first modified example.

[0016] Figure 7 It is a schematic physical wiring diagram of the hydrogen sensor, the vehicle ECU, and the vehicle wiring harness having a trunk line and branch line components in the first modified example.

[0017] Figure 8It is an explanatory diagram showing the relationship between the hydrogen sensor identification terminal, the communication bus, and the identifier set for the hydrogen sensor in the first modification example.

[0018] Figure 9 It is a circuit block diagram of the sensor system in the second modification example.

[0019] Figure 10 It is an explanatory diagram showing the relationship between the hydrogen sensor identification terminal, the communication bus, and the identifier set for the hydrogen sensor in the second modification example. Detailed implementation mode

[0020] Figure 1A It is a side view showing the schematic structure of the fuel cell vehicle 12 equipped with the sensor system 10 according to the present embodiment. The sensor system 10 includes sensors 51 to 54. Figure 1B It is a top view showing the schematic structure of the fuel cell vehicle 12. Figure 2 It is a circuit block diagram of the sensor system 10.

[0021] In Figure 1A and Figure 1B the fuel cell vehicle 12 has a base frame 14. On this base frame 14, the front wheels WF, the rear wheels WR, and the drive motor 16 that drives the front wheels WF are supported directly or through a structure. In addition, on this base frame 14, the fuel cell stack 18, the first hydrogen tank 20a, the second hydrogen tank 20b, the piping 21, the battery 19 (high-voltage battery), etc. are supported directly or through a structure. Furthermore, Figure 1A and Figure 1B the arrows shown respectively indicate the front-back, left-right, and up-down directions.

[0022] The fuel cell vehicle 12 has a battery 19, a drive motor 16, and a fuel cell system. The battery 19 stores the electricity generated by the electrochemical reaction of the fuel cell stack 18. The drive motor 16 is a traveling drive source and is driven by the energy of the battery 19 and / or the energy of the fuel cell stack 18. The fuel cell system has a fuel cell stack 18, the first hydrogen tank 20a, the second hydrogen tank 20b, and an air pump (not shown). The fuel cell stack 18 has, for example, a membrane electrode assembly (MEA) which is composed of a cathode electrode and an anode electrode sandwiching a solid polymer electrolyte membrane impregnated with water in a perfluorosulfonic acid thin film. The first hydrogen tank 20a and the second hydrogen tank 20b supply hydrogen as a reaction gas to the fuel cell stack 18. The air pump supplies an oxygen-containing gas (air) as the other reaction gas to the fuel cell stack 18.

[0023] The fuel cell vehicle 12 has a front hood 22, a front window 24, a roof 26, a rear gate 28, a floor 30, a luggage compartment board 32, a dash panel 34, a front seat 42, a rear seat 44, etc. A display device 35 such as a multi-functional information display is installed on the dash board at the upper part of the dash panel 34.

[0024] Moreover, the vehicle ECU 36 (vehicle control ECU), together with the fuel cell stack 18 and the drive motor 16, is arranged in the motor compartment 38 under the front hood 22. The vehicle ECU 36 manages and controls the sensor system 10 of the fuel cell vehicle 12 and manages and controls the whole fuel cell vehicle 12. In addition, the fuel cell stack 18 is housed in the hydrogen isolation cover 48 and kept airtight.

[0025] A battery 19 is arranged between the luggage compartment board 32 under the rear seat 44 and the chassis 14. Between the luggage compartment board 32 under the luggage compartment 46 and the chassis 14, a first hydrogen tank 20a and a second hydrogen tank 20b are arranged in the front-rear direction. The first hydrogen tank 20a, the second hydrogen tank 20b and the fuel cell stack 18 are interconnected through a pipe (hydrogen flow path) 21 passing under the floor 30 (refer to Figure 1A ).

[0026] Moreover, hydrogen sensors 51 to 54 as gas sensors are installed at four positions inside the fuel cell vehicle 12. The hydrogen sensors 51 and 52 are respectively installed at positions P1 and P2. The positions P1 and P2 are positions under the front hood 22 and above the hydrogen isolation cover 48. The hydrogen sensors 51 and 52 detect gas leakage from the fuel cell stack 18. The hydrogen sensors 53 and 54 are respectively installed at positions P3 and P4. The positions P3 and P4 are positions under the luggage compartment board 32 and above the vicinity of the shut-off valves of the first hydrogen tank 20a and the second hydrogen tank 20b. The hydrogen sensors 53 and 54 respectively detect gas leakage from the first hydrogen tank 20a and the second hydrogen tank 20b.

[0027] Hydrogen is a gas lighter than air. Therefore, in the event that gas (hydrogen) leaks from the fuel cell stack 18, the first hydrogen tank 20a and the second hydrogen tank 20b which are the objects of gas leakage detection, the leaked gas stays in the upper recess. Therefore, the hydrogen sensors 51, 52, 53, 54 are installed at positions P1, P2, P3, P4 which are recesses (hydrogen accumulation parts) opening substantially downward.

[0028] The vehicle ECU 36 and the hydrogen sensors 51 to 54 each have a computer including a microcomputer. The microcomputer has a CPU (Central Processing Unit), a ROM (Read-Only Memory, which also includes an EEPROM: Electrically Erasable Programmable Read Only Memory) as a memory, and a RAM (Random Access Memory). In addition, the microcomputer also has input / output devices such as an A / D converter and a D / A converter, and a timer as a timing unit. The CPU reads and executes the program recorded in the ROM. Accordingly, the CPU functions as various function implementation units (function implementation mechanisms), such as a control unit, an arithmetic unit, and a processing unit, etc.

[0029] As Figure 2 shown, in the present embodiment, the vehicle ECU 36 has an ID comparison unit 36v and the like as functional units. The hydrogen sensors 51 to 54 have ID setting units (identifier setting units) 51s, 52s, 53s, 54s and the like as functional units.

[0030] The vehicle ECU 36 and the hydrogen sensors 51 to 54 each have rewritable storage units 36m, 51m, 52m, 53m, 54m. The storage units 36m, 51m to 54m are preferably non-volatile memories. However, the storage unit 36m and the storage units 51m to 54m can also be volatile memories.

[0031] The vehicle ECU 36 and the hydrogen sensors 51 to 54 are interconnected with the vehicle wiring harness 60.

[0032] As Figure 2 shown, the vehicle wiring harness 60 has a main line 62 as a CAN bus (communication bus) and four branch components (branch assemblies) 71, 72, 73, 74. The four branch components 71, 72, 73, 74 extend from positions Q1, R2, Q3, Q4 on the main line 62. The positions Q1, R2, Q3, Q4 on the main line 62 are configured to be substantially coincident with the positions P1, P2, P3, P4 of the fuel cell vehicle 12 when the main line 62 is wired to the fuel cell vehicle 12.

[0033] As Figure 2As shown, the main line 62 has two systems of CAN buses. The main line 62 includes a first communication bus CAN1 and a second communication bus CAN2. At positions Q1, Q3, and Q4 on the first communication bus CAN1, hydrogen sensors 51, 53, and 54 are connected via branch line components 71, 73, and 74. At position R2 on the second communication bus CAN2, a hydrogen sensor 52 is connected via a branch line component 72.

[0034] In addition, the main line 62 is not limited to the CAN bus and can also be replaced by other communication buses such as LIN buses, other FlexRay buses, etc.

[0035] Figure 3 It is a schematic physical wiring diagram showing a vehicle wiring harness 60 having a main line 62 and branch line components 71 to 74, a vehicle ECU 36, a low-voltage battery 37, and hydrogen sensors 51 to 54.

[0036] The main line 62 is composed of a power line and a GND line extending from a low-voltage battery 37 (not shown in Figure 1A 、 Figure 1B configured in the motor compartment 38), and a first communication bus CAN1 and a second communication bus CAN2 extending from the vehicle ECU 36. The first communication bus CAN1 includes a CAN1-L line and a CAN1-H line. The second communication bus CAN2 includes a CAN2-L line and a CAN2-H line. Branch line components 71 to 74 are respectively installed at positions Q1, R2, Q3, and Q4 on the main line 62, and the branch line components 71 to 74 have connectors 81 to 84 with leads.

[0037] When the main line 62 is wired in the fuel cell vehicle 12, it starts from the low-voltage battery 37 and the vehicle ECU 36 (starting point). The main line 62 is configured from the vehicle ECU 36 to the position P1 where the hydrogen sensor 51 is installed. The branch line component 71 is configured at position Q1 on the first communication bus CAN1. Then, the main line 62 is configured to the position P2 where the hydrogen sensor 52 is installed. The branch line component 72 is configured at position R2 which is the terminal (end point) of the second communication bus CAN2. And the main line 62 is laid under the floor 30 and configured to the installation position P3 of the hydrogen sensor 53. The branch line component 73 is configured at position Q3 of the first communication bus CAN1. The main line 62 is configured to the installation position P4 of the hydrogen sensor 54. Position Q4 is the terminal (end point) of the first communication bus CAN1, and the branch line component 74 is configured at this position Q4.

[0038] In such a configuration structure (wiring structure), the vehicle ECU 36 is configured at the starting end (starting point) of the trunk line 62 (transmission line). A terminal resistor (not shown) for suppressing the reflection of the transmission signal (CAN data signal) is installed at the input and output ends of the vehicle ECU 36. In addition, the hydrogen sensor 54 is configured at the terminal (end point) of the trunk line 62 (transmission line). A terminal resistor (not shown) for suppressing the reflection of the transmission signal (CAN data signal) is installed at the input and output ends of the hydrogen sensor 54.

[0039] The branch line assemblies 71 to 74 are respectively installed at positions Q1, R2, Q3, and Q4 of the trunk line 62. Female 6-pole connectors 81 to 84 are installed at the ends of the branch line assemblies 71 to 74 close to the hydrogen sensors 51 to 54. The hydrogen sensors 51 to 54 are respectively arranged at positions P1 to P4 facing positions Q1, R2, Q3, and Q4 on the trunk line 62. Male 6-pole connectors 51c to 54c are provided on the hydrogen sensors 51 to 54. The connectors 81 to 84 of the branch line assemblies 71 to 74 are respectively configured in a manner that can be freely detached from the connectors 51c to 54c of the hydrogen sensors 51 to 54.

[0040] The 6-pole connectors 81 to 84 of the branch line assemblies 71 to 74 have female pins (terminals) of GND-G, power supply-P, CAN-H, CAN-L, identification A, and identification B, respectively. On the other hand, the 6-pole connectors 51c to 54c of the hydrogen sensors 51 to 54 correspond to the above and also have male pins (male pins) (terminals) of GND-G, power supply-P, CAN-H, CAN-L, identification A, and identification B, respectively. The connectors 81 to 84 on the trunk line 62 side and the connectors 51c to 54c on the hydrogen sensors 51 to 54 side are configured so that they cannot be mated in the reverse direction (upside down).

[0041] In addition, from Figure 3 It can be seen that the connectors 81 to 84 on the branch line components 71 to 74 of the present embodiment have pins ( Figure 3 In addition to the four pins P, G, H, and L in the sensor, there is also at least one identification pin. This is the minimum structure for identifying hydrogen sensors 51 to 54 of the same specification.

[0042] Here, identification structures 1 to 4 unique to the connectors 81 to 84 and identifiers set to the hydrogen sensors 51 to 54 are described.

[0043] like Figure 3 As shown, the identification A pin and the GND-G pin of the connector 81 are short-circuited by an inter-pin shorting line, i.e., a jumper line, etc. No inter-pin shorting line is provided on the identification B pin of the connector 81. Hereinafter, such an identification structure of the connector 81 is referred to as identification structure 1.

[0044] When the connector 81 of the identification structure 1 is engaged with the connector 51c of the hydrogen sensor 51, the identification A pin (identification terminal A) of the connector 51c is connected to the ground potential via the inter-pin short circuit line. The identification A pin of the connector 51c becomes the ground state (GND). The identification B pin (identification terminal B) of the connector 51c is not connected to any potential. The identification B pin of the connector 51c becomes the open state (OPEN).

[0045] No inter-pin short circuit line is provided on either the identification A pin or the identification B pin of the connector 82. Hereinafter, such an identification structure of the connector 82 is referred to as the identification structure 2.

[0046] When the connector 82 of the identification structure 2 is engaged with the connector 52c of the hydrogen sensor 52, neither the identification A pin nor the identification B pin of the connector 52c is connected to any potential. The identification A pin and the identification B pin of the connector 52c are respectively in the open state (OPEN).

[0047] No inter-pin short circuit line is provided on the identification A pin of the connector 83. The identification B pin and the GND-G pin of the connector 83 are short-circuited via the inter-pin short circuit line. Hereinafter, such an identification structure of the connector 83 is referred to as the identification structure 3.

[0048] When the connector 83 of the identification structure 3 is engaged with the connector 53c of the hydrogen sensor 53, the identification A pin of the connector 53c is not connected to any potential. The identification A pin of the connector 53c becomes the open state (OPEN). The identification B pin of the connector 53c is connected to the ground potential via the inter-pin short circuit line. The identification B pin of the connector 53c becomes the ground state (GND).

[0049] In the connector 84, the identification A pin, the identification B pin, and the GND-G pin of the connector 84 are short-circuited via the inter-pin short circuit line. Hereinafter, such an identification structure of the connector 84 is referred to as the identification structure 4.

[0050] When the connector 84 of the identification structure 4 is engaged with the connector 54c of the hydrogen sensor 54, the identification A pin and the identification B pin of the connector 54c are respectively connected to the ground potential via the inter-pin short circuit line. The identification A pin and the identification B pin of the connector 54c respectively become the ground state (GND).

[0051] The CAN-H pins of connectors 81, 83, and 84 are respectively connected to the CAN1-H line of the first communication bus CAN1. Therefore, the CAN-H pins of hydrogen sensors 51, 53, and 54 are respectively connected to the CAN1-H line of the first communication bus CAN1. The CAN-L pins of connectors 81, 83, and 84 are connected to the CAN1-L line of the first communication bus CAN1. Therefore, the CAN-L pins of hydrogen sensors 51, 53, and 54 are respectively connected to the CAN1-L line of the first communication bus CAN1.

[0052] The CAN-H pin of connector 82 is connected to the CAN2-H line of the second communication bus CAN2. Therefore, the CAN-H pin of hydrogen sensor 52 is connected to the CAN2-H line of the second communication bus CAN2. The CAN-L pin of connector 82 is connected to the CAN2-L line of the second communication bus CAN2. Therefore, the CAN-L pin of hydrogen sensor 52 is connected to the CAN2-L line of the second communication bus CAN2.

[0053] In this way, in each branch component 71 to 74, the insertion positions of the jumpers in connectors 81 to 84 are different. Therefore, the identification structures 1 to 4 of connectors 81 to 84 are different from each other. In addition, branch components 71, 73, and 74 are connected to the first communication bus CAN1, and branch component 72 is connected to the second communication bus CAN2. That is, hydrogen sensors 51, 53, and 54 and hydrogen sensor 52 are connected to different communication buses from each other. Accordingly, the vehicle ECU 36 can electrically and uniquely identify (distinguish) hydrogen sensors 51 to 54.

[0054] When the power switch (not shown) of the fuel cell vehicle 12 is turned on and power is supplied to the hydrogen sensors 51 to 54 from the low-voltage battery 37, the ID setting units 51s, 52s, 53s, and 54s of the hydrogen sensors 51 to 54 perform the following determination. The ID setting units 51s, 52s, 53s, and 54s determine the connection state of the identification A pins of the connectors 51c to 54c based on the identification structures 1 to 4. Specifically, the ID setting units 51s, 52s, 53s, and 54s determine whether the identification A pin is in a grounded state (GND) or an open state (OPEN). Similarly, the ID setting units 51s, 52s, 53s, and 54s determine the connection state of the identification B pins of the connectors 51c to 54c based on the identification structures 1 to 4. Specifically, the ID setting units 51s, 52s, 53s, and 54s determine whether the identification B pin is in a grounded state (GND) or an open state (OPEN). Moreover, the ID setting units 51s, 52s, 53s, and 54s determine whether the hydrogen sensors 51 to 54 are connected to the first communication bus CAN1 or the second communication bus CAN2 based on the CAN-H pins and CAN-L pins of the connectors 51c to 54c. In addition, in the following description, the CAN-H pins and CAN-L pins of the connectors 51c to 54c are sometimes collectively referred to as communication terminals.

[0055] When it is determined that the hydrogen sensors 51, 53, and 54 are connected to the first communication bus CAN1, the ID setting units 51s, 53s, and 54s set an identifier based on the standard format for the connectors 51c, 53c, and 54c. The ID setting units 51s, 53s, and 54s select an identifier according to the connection state of the identification A pin and the connection state of the identification B pin of the connectors 51c, 53c, and 54c. The ID setting units 51s, 53s, and 54s write the selected identifier into the storage units 51m, 53m, and 54m.

[0056] The standard format refers to one of the forms (modes) of data frames in the CAN bus. The identifier based on the standard format is represented by 11-bit data. In addition, in the following description, the identifier based on the standard format is sometimes referred to as the standard ID.

[0057] On the other hand, when it is determined that the hydrogen sensor 52 is connected to the second communication bus CAN2, the ID setting unit 52s sets an identifier based on the extended format for the connector 52c. The ID setting unit 52s selects an identifier according to the connection state of the identification A pin and the connection state of the identification B pin of the connector 52c. The ID setting unit 52s writes the selected identifier into the storage unit 52m.

[0058] The extended format refers to one of the forms (modes) of data frames in the CAN bus. The identifier based on the extended format is represented by 29-bit data. In this regard, the extended format is different from the standard format. In this embodiment, the vehicle ECU 36 can transmit and receive both data frames based on the standard format and data frames based on the extended format. In addition, the vehicle ECU 36 can recognize the identifier based on the standard format and the identifier based on the extended format as different identifiers. Furthermore, in the following description, the identifier based on the extended format is sometimes referred to as the extended ID.

[0059] Figure 4 An example showing the relationship between the identification terminal, the communication bus, and the identifiers set for the hydrogen sensors 51 to 54.

[0060] The hydrogen sensor 51 is installed at the position P1 above the fuel cell stack 18. In the hydrogen sensor 51, the identification A pin (terminal A, identification terminal A) is in the grounded state (GND). The identification B lead (terminal B, identification terminal B) is in the open state (OPEN). The communication terminal of the hydrogen sensor 51 is connected to the first communication bus CAN1. Therefore, the identifier CAN-ID_A based on the standard format (standard ID) is written in the storage unit 51m of the hydrogen sensor 51.

[0061] The hydrogen sensor 52 is installed at the position P2 above the fuel cell stack 18. In the hydrogen sensor 52, both the identification A pin and the identification B pin are in the open state (OPEN). The communication terminal of the hydrogen sensor 52 is connected to the second communication bus CAN2. Therefore, the identifier CAN-EID_A based on the extended format (extended ID) is written in the storage unit 52m of the hydrogen sensor 52.

[0062] The hydrogen sensor 53 is installed at the position P3 above the first hydrogen tank 20a. In the hydrogen sensor 53, the identification A pin is in the open state (OPEN). The identification B pin is in the grounded state (GND). The communication terminal of the hydrogen sensor 53 is connected to the first communication bus CAN1. Therefore, the identifier CAN-ID_B based on the standard format is written in the storage unit 53m of the hydrogen sensor 53.

[0063] The hydrogen sensor 54 is installed at the position P4 above the second hydrogen tank 20b. In the hydrogen sensor 54, both the identification A pin and the identification B pin are in the grounded state (GND). The communication terminal of the hydrogen sensor 54 is connected to the first communication bus CAN1. Therefore, the identifier CAN-ID_C based on the standard format is written in the storage unit 54m of the hydrogen sensor 54.

[0064] In addition, before writing the identifiers in the storage units 51m to 54m, the four hydrogen sensors 51 to 54 are not particularly different. That is, the hydrogen sensors 51 to 54 are hydrogen sensors of a single specification (the same specification), which are suitable for mass production. Therefore, the manufacturing cost and parts management cost of the hydrogen sensors 51 to 54 can be reduced.

[0065] Next, the steps of setting identifiers for the hydrogen sensors 51 to 54 in the sensor system 10 according to the present embodiment will be described. Taking the process of installing the hydrogen sensors 51 to 54 on the fuel cell vehicle 12 as an example for description.

[0066] Figure 5 It shows a schematic process of installing the hydrogen sensors 51 to 54 on the vehicle wiring harness 60.

[0067] Actually, before the vehicle wiring harness installation process in step S1, Figure 3 The vehicle wiring harness 60 (the main line 62 equipped with the branch components 71 to 74) shown and the components other than the hydrogen sensors 51 to 54 have been assembled on the fuel cell vehicle 12.

[0068] In the vehicle wiring harness installation process of step S1, with the power supply of the fuel cell vehicle 12 disconnected, the starting end of the vehicle wiring harness 60 is installed on the vehicle ECU 36. The remaining part of the vehicle wiring harness 60 is arranged along the specified parts on the fuel cell vehicle 12 as described above. In the present embodiment, first, the vehicle wiring harness 60 is arranged such that the branch component 71 at the position Q1 on the main line 62 faces the position P1. Next, the vehicle wiring harness 60 is arranged such that the branch component 72 at the position R2 on the main line 62 faces the position P2. Then, the vehicle wiring harness 60 is laid from the motor compartment 38 to the rear lower side and laid under the floor 30. The vehicle wiring harness 60 is arranged such that the branch components 73 and 74 at the positions Q3 and Q4 on the main line 62 face the positions P3 and P4 respectively. Accordingly, the wiring of the main line 62 of the vehicle wiring harness 60 is completed.

[0069] Next, in the sensor installation process of step S2, the hydrogen sensors 51 to 54 are respectively installed at the positions P1 to P4 in the fuel cell vehicle 12. In this case, the hydrogen sensors 51 to 54 have the same specifications (single specification, same type) and can be installed at any of the positions P1 to P4. Therefore, there will be no so-called misassembly. In addition, the hydrogen sensors 51 to 54 can also be installed on the fuel cell vehicle 12 before the vehicle wiring harness 60 is installed on the fuel cell vehicle 12.

[0070] Next, enter the connector connection process of step S3. Hydrogen sensors 51 to 54 are respectively fixed at positions P1 to P4. Branch line assemblies 71 to 74 are arranged near the connectors 51c to 54c of the hydrogen sensors 51 to 54. The connectors 81 to 84 of the branch line assemblies 71 to 74 are respectively fitted into the connectors 51c to 54c of the hydrogen sensors 51 to 54. Accordingly, each male pin of the connectors 51c to 54c of the hydrogen sensors 51 to 54 is mechanically and electrically connected to each female pin of the connectors 81 to 84 of the branch line assemblies 71 to 74.

[0071] Furthermore, in the power-on (ON) process of step S4, the power supply of the fuel cell vehicle 12 is made in the on state. Accordingly, power is supplied from the low-voltage battery 37 to the vehicle ECU 36. In addition, power is supplied from the low-voltage battery 37 to the hydrogen sensors 51 to 54 through the power line and the GND line of the main line 62.

[0072] Triggered by the power supply, each CPU of the hydrogen sensors 51 to 54 starts initial setting. The initial setting includes the ID setting process of step S5.

[0073] In step S5, the ID setting units 51S to 54S of the hydrogen sensors 51 to 54 determine the connection states of the identification A pins and the identification B pins of the connectors 51c to 54c. That is, the ID setting units 51s to 54s determine whether the identification A pin is in the grounded state (GND) or the open state (OPEN). In addition, the ID setting units 51s to 54s determine whether the identification B pin is in the grounded state (GND) or the open state (OPEN). The above determination of the ID setting units 51s to 54s is made according to the identification structures 1 to 4 (which pins are short-circuited to which pins) given to the connectors 81 to 84 of the branch line assemblies 71 to 74 through jumpers or the like. Moreover, the ID setting units 51s to 54s determine whether the communication bus to which the hydrogen sensors 51 to 54 are connected is the first communication bus CAN1 or the second communication bus CAN2. The above determination of the ID setting units 51s to 54s is made according to the CAN-H pin and the CAN-L pin (communication terminals) of the connectors 51c to 54c.

[0074] The ID setting units 51s to 54s set the identifier (ID) in different formats according to whether the communication bus connected to the communication terminal is the first communication bus CAN1 or the second communication bus CAN2.

[0075] When it is determined that the communication bus connected to the communication terminal is the first communication bus CAN1, the ID setting units 51s to 54s set the identifier based on the standard format. The ID setting units 51s to 54s select the identifier according to the connection states of the identification A pin and the identification B pin. The ID setting units 51s to 54s write the selected identifier into the storage units 51m to 54m.

[0076] When it is determined that the communication bus connected to the communication terminal is the second communication bus CAN2, the ID setting units 51s to 54s set an identifier based on the extended format. The ID setting units 51s to 54s select an identifier according to the connection state of the A pin and the connection state of the B pin. The ID setting units 51s to 54s write the selected identifier into the storage units 51m to 54m.

[0077] That is, in this embodiment, each of the ID setting units 51s to 54s sets an identifier (ID) in a different format according to the connection state of the A pin, the connection state of the B pin, and the difference in the communication bus connected to the communication terminal. The connection state of the A pin and the connection state of the B pin are either the ground state (GND) or the open state (OPEN). "The difference in the communication bus connected to the communication terminal" means whether the communication bus connected to the communication terminal is the first communication bus CAN1 or the second communication bus CAN2.

[0078] Next, step S6 is entered. Step S6 is a process of sending an identifier (ID) to the vehicle ECU 36. In step S6, the ID setting units 51S to 54S of the hydrogen sensors 51 to 54 read the unique identifier (ID) of the hydrogen sensors 51 to 54 from the storage units 51m to 54m. The ID setting units 51s to 54s send the unique identifier (ID) to the vehicle ECU 36 through the main line 62.

[0079] Next, step S7 is entered. The vehicle ECU 36 has an ID comparison unit 36v. This ID comparison unit 36v determines whether there are multiple identical identifiers among the identifiers of the hydrogen sensors 51 to 54 received by the vehicle ECU 36.

[0080] When it is determined in step S7 that there are multiple identical identifiers (step S7: YES), step S8 is entered. The vehicle ECU 36 determines that an abnormality has occurred because any one of the hydrogen sensors 51 to 54 has not operated normally.

[0081] An abnormality of the hydrogen sensors 51 to 54 is, for example, a failure caused by a disconnection of the A pin or a disconnection of the B pin. When such a failure occurs, the identifier of the failed hydrogen sensor is changed to the same identifier as that of the normal hydrogen sensor. Therefore, the vehicle ECU 36 cannot distinguish the failed hydrogen sensor from the normal sensor.

[0082] Therefore, when the vehicle ECU 36 determines that an abnormality has occurred in any one of the hydrogen sensors 51 to 54, step S9 is entered. The vehicle ECU 36 closes a main cut-off valve (not shown) on the pipe 21. That is, the vehicle ECU 36 cuts off the hydrogen supply to the fuel cell stack 18.

[0083] On the other hand, when it is determined in step S7 that there are no multiple identical identifiers (step S7: NO), the process proceeds to step S10. The vehicle ECU 36 determines that the hydrogen sensors 51 to 54 are operating normally.

[0084] Next, the process proceeds to step S11. Step S11 is a process in which the vehicle ECU 36 compares the identifiers (IDs) of the hydrogen sensors 51 to 54. In the storage unit 36m of the vehicle ECU 36, identifiers corresponding to the positions Q1, R2, Q3, and Q4 of the main line 62 are stored in advance. The ID comparison unit 36v of the vehicle ECU 36 compares the unique identifiers sent from the ID setting units 51s to 54s of the hydrogen sensors 51 to 54 with the identifiers corresponding to the positions Q1, R2, Q3, and Q4 of the main line 62.

[0085] Based on the comparison result, the vehicle ECU 36 can identify (distinguish) the unique identifiers of the hydrogen sensors 51 to 54 installed at the positions P1 to P4.

[0086] [Invention that can be grasped from the embodiment]

[0087] The invention that can be grasped from the above embodiment is described below. In addition, for ease of understanding, reference numerals used in the above embodiment are attached to each component, but the component is not limited to the component to which the reference numeral is attached.

[0088] The hydrogen sensors (sensors) 51 to 54 of the present embodiment are connected to the vehicle ECU (control device) 36 via either the first communication bus CAN1 (one communication bus) or the second communication bus CAN2 (the other communication bus) constructed on the fuel cell vehicle (moving body) 12, and are identified by unique identifiers. The hydrogen sensors 51 to 54 have: CAN-H pins and CAN-L pins (communication terminals) that are connected to either the first communication bus CAN1 or the second communication bus CAN2 of the two communication buses and communicate with the vehicle ECU 36; identification A pins and identification B pins (identification terminals) that are set to be in either an open state (OPEN) not connected to any potential or a grounded state (GND) connected to the ground potential; and ID setting units (identifier setting units) 51s to 54s that set the identifiers of the hydrogen sensors 51 to 54 according to the connection states of the identification A pins and the identification B pins and the difference in the communication buses to which the CAN-H pins and the CAN-L pins are connected.

[0089] The ID setting units 51s to 54s set identifiers in different formats according to whether the communication bus connected to the CAN-H pin and the CAN-L pin is the first communication bus CAN1 or the second communication bus CAN2. The ID setting units 51s to 54s set identifiers in either a standard format (standard ID) or an extended format (extended ID).

[0090] Assume that the hydrogen sensor 51 at the position P1 above the fuel cell stack 18 fails and the identification A pin of the hydrogen sensor 51 is disconnected. In this case, the connection state of the identification A pin changes from the grounded state (GND) to the open state (OPEN). The connection state of the identification B pin remains in the open state (OPEN).

[0091] In this case, the identifier of the hydrogen sensor 51 changes from the identifier CAN-ID_A to a new identifier CAN-ID_D according to the change in the connection state of the identification A pin. This new identifier CAN-ID_D is an example of an identifier based on the standard format set when both the identification A pin and the identification B pin are in the open state (OPEN).

[0092] In addition to the failed hydrogen sensor 51, the sensor system 10 has another normal hydrogen sensor 52. The connection state of the identification A pin of the other normal hydrogen sensor 52 is in the open state (OPEN) and the connection state of the identification B pin is in the open state (OPEN). However, in this embodiment, the hydrogen sensor 52 is connected to the second communication bus CAN2. Therefore, the hydrogen sensor 52 is set with an identifier CAN-EID_A based on the extended format.

[0093] The vehicle ECU 36 recognizes identifiers with different formats as different identifiers from each other. Therefore, the vehicle ECU 36 will not be confused by the standard format identifier CAN-ID_D of the failed hydrogen sensor 51 and the extended format identifier CAN-EID_A of the normal hydrogen sensor 52. In addition, the identifier CAN-ID_A that the hydrogen sensor 51 used before the failure no longer exists on the main line 62. Therefore, the vehicle ECU 36 can determine the failure location (the failed hydrogen sensor 51).

[0094] In this way, in the hydrogen sensors 51 to 54 according to this embodiment, even if the number of hydrogen sensors for which identifiers are set increases, confusion of identifiers can be prevented.

[0095] In addition, preferably, for a combination in which both the identification A pin and the identification B pin, such as the combination of the identification A pin and the identification B pin of the hydrogen sensor 51 after a failure, are in an open state (OPEN), an identifier based on the standard format is not set. Accordingly, no identifier (not allocated) is set for the failed hydrogen sensor 51. Therefore, the vehicle ECU 36 will not confuse the failed hydrogen sensor 51 with other hydrogen sensors 52 to 54. In addition, the identifier CAN-ID_A used by the hydrogen sensor 51 before the failure no longer exists on the main line 62. Therefore, the vehicle ECU 36 can determine the failure location (the failed hydrogen sensor 51).

[0096] In addition, the identification A pin of the hydrogen sensor 51 may change from the grounded state (GND) to the open state (OPEN) due to a broken wire or the like. On the other hand, the possibility of a reverse change is low. That is, the possibility that the identification B pin of the hydrogen sensor 51 changes from the open state (OPEN) to the grounded state (GND) due to a short circuit is low.

[0097] When a failure occurs in the identification A pin of the hydrogen sensor 51, it is possible that the sensor having a combination of connection states of the identification A pin and the identification B pin of the failed hydrogen sensor 51 is the hydrogen sensor 52. Therefore, in the present embodiment, the hydrogen sensor 51 and the hydrogen sensor 52 are connected to different communication buses. The identifier of the hydrogen sensor 51 is set in a format different from that of the identifier of the hydrogen sensor 52. Accordingly, even when a failure occurs in the hydrogen sensor 51, the vehicle ECU 36 can reliably prevent the failed hydrogen sensor 51 from being confused with the normal hydrogen sensor 52.

[0098] In addition, in the sensor system 10 of the present embodiment, the plurality of hydrogen sensors include a hydrogen sensor 51 (first gas sensor) and a hydrogen sensor 52 (second gas sensor), wherein the hydrogen sensor 51 detects hydrogen leaked from the fuel cell stack 18, the hydrogen sensor 52 detects hydrogen leaked from the fuel cell stack 18, and any one of the identification A pin (first terminal) and the identification B pin (second terminal) of the hydrogen sensor 51 (first gas sensor) is set to the grounded state (GND), and both the identification A pin (first terminal) and the identification B pin (second terminal) of the hydrogen sensor 52 (second gas sensor) are set to the open state (OPEN).

[0099] Both the identification A pin and the identification B pin of the hydrogen sensor 52 are in the open state (OPEN). As described above, the hydrogen sensor 52 is not easily affected by a broken wire. Therefore, the gas leakage detection function of the fuel cell stack 18 can be made redundant by the two hydrogen sensors 51 and 52. As a result, the detection reliability of the sensor system 10 can be significantly improved.

[0100] [First Variant Example]

[0101] Refer to Figures 6 - 8 to describe the first variant example.

[0102] In the above-described embodiment, the position where the hydrogen sensor 54 is connected to the first communication bus CAN1 is position Q4. In Figures 6 - 8 the shown first variant example, the difference is that the hydrogen sensor 55 is connected to position R4 of the second communication bus CAN2.

[0103] In addition, for the structural elements that are the same as those in the above-described embodiment, in Figures 6 - 8 the last two digits are appended with the same reference numerals in the accompanying drawings and the description thereof is omitted.

[0104] As Figure 8 shown, similar to the hydrogen sensor 54, the hydrogen sensor 55 is installed at position P4 above the second hydrogen tank 20b. Both the identification A pin and the identification B pin of the hydrogen sensor 55 are in the grounded state (GND). On the other hand, the communication terminal of the hydrogen sensor 55 is not connected to the first communication bus CAN1 but to the second communication bus CAN2. Therefore, the identifier CAN-EID_B based on the extended format is written into the storage unit 55m of the hydrogen sensor 55. The identifier based on the standard format is not written into the storage unit 55m of the hydrogen sensor 55.

[0105] According to this first variant example, even when any one of the hydrogen sensors 51, 52, 53, 55 fails, it is possible to prevent the identifiers of all combinations of the failed hydrogen sensor and the normal hydrogen sensors from being duplicated (confused).

[0106] For example, when the identification A pin of the hydrogen sensor 55 is disconnected, the identification A pin of the hydrogen sensor 55 becomes an open state (OPEN). The identification B pin of the hydrogen sensor 55 remains in the grounded state (GND). This is the same combination as the identification A pin and the identification B pin of the normal hydrogen sensor 53. However, the hydrogen sensor 55 is connected to the second communication bus CAN2 and is set with an identifier based on the extended format. On the other hand, the hydrogen sensor 53 is set with the identifier CAN-ID_B based on the standard format. Therefore, the identifiers of the hydrogen sensor 55 and the hydrogen sensor 53 do not duplicate.

[0107] In addition, when the identification B pin of the hydrogen sensor 55 is disconnected, the identification B pin of the hydrogen sensor 55 becomes an open state (OPEN). The identification A pin of the hydrogen sensor 55 remains in the grounded state (GND). This is the same combination as the identification A pin and the identification B pin of the normal hydrogen sensor 51. However, the hydrogen sensor 55 is connected to the second communication bus CAN2. The hydrogen sensor 55 is set with an identifier based on the extended format. On the other hand, the hydrogen sensor 51 is set with an identifier CAN-ID_A based on the standard format. Therefore, the identifiers of the hydrogen sensor 55 and the hydrogen sensor 51 do not overlap.

[0108] Furthermore, in the hydrogen sensor 51, the connection state of the identification A pin and the connection state of the identification B pin are GND / OPEN. In the hydrogen sensor 53, the connection state of the identification A pin and the connection state of the identification B pin are OPEN / GND. When a 1-bit fault occurs in either the hydrogen sensor 51 or the hydrogen sensor 53, in either the hydrogen sensor 51 or the hydrogen sensor 53, the connection state of the identification A pin and the connection state of the identification B pin become OPEN / OPEN. That is, the connection state of the identification A pin and the connection state of the identification B pin in either the hydrogen sensor 51 or the hydrogen sensor 53 become the same combination (OPEN / OPEN) as that of the hydrogen sensor 52. However, the hydrogen sensor 51 and the hydrogen sensor 53 are connected to the first communication bus CAN1, and the identifiers of the hydrogen sensor 51 and the hydrogen sensor 53 are set by the standard format. On the other hand, the identifier CAN-EID_A of the hydrogen sensor 52 is set by the extended format. Therefore, the identifiers of the hydrogen sensor 51 and the hydrogen sensor 53 do not overlap with the identifier of the hydrogen sensor 52.

[0109] Thus, according to the first modification example, even when a fault occurs in any one of the four hydrogen sensors 51, 52, 53, and 55, overlap (confusion) of identifiers can be prevented.

[0110] In addition, the first modification is applicable not only to the case where the number of identification terminals of each sensor is two, but also to the case where the number of identification terminals of each sensor is three or more. In a sensor having three or more identification terminals, when the number of identification terminals in the grounded state (GND) is odd, the sensor is connected to the first communication bus CAN1. The identifier of such a sensor is set in a standard format. In a sensor having three or more identification terminals, when the number of identification terminals in the grounded state (GND) is even, the sensor is connected to the second communication bus CAN2. Additionally, in a sensor having three or more identification terminals, when the number of identification terminals in the grounded state (GND) is zero (when all identification terminals are in the open state (OPEN)), the sensor is connected to the second communication bus CAN2. The identifier of such a sensor is set in an extended format. According to this structure, even in the case of assuming a 1-bit failure, it is possible to prevent duplication (confusion) of identifiers between a faulty sensor and a normal sensor. Compared with the prior art, the number of sensors for which identifiers can be set can be increased.

[0111] [Second Modification Example]

[0112] Refer to Figure 9 and Figure 10 to describe the second modification example.

[0113] In addition, in the second modification example, for structural elements that are the same as those in the above-described embodiment and the first modification example, the same reference numerals are appended to the last two digits in Figure 9 and Figure 10 and the description thereof is omitted.

[0114] This second modification example is envisaged to be applied to large vehicles such as trucks or buses equipped with multiple fuel cell stacks.

[0115] In the above-described embodiment, four hydrogen sensors 51 to 54 are connected to the main line 62 (the first communication bus CAN1 and the second communication bus CAN2). In Figure 9 and Figure 10 shown in the second modification example, the difference is that eight hydrogen sensors 151 to 154, 251 to 254 are connected to the main line 62.

[0116] The sensor system 210 in this second modification example has two control devices (ECUs).

[0117] As Figure 9 and 10As shown, the FCECU136, which is the first control device (ECU), controls the first controlled object 130. The first controlled object 130 includes the first fuel cell stack 118, the first hydrogen tank 120a, and the second hydrogen tank 120b.

[0118] The FCECU236, which is the second control device (ECU), controls the second controlled object 230. The second controlled object 230 includes the second fuel cell stack 218, the third hydrogen tank 220a, and the fourth hydrogen tank 220b.

[0119] Next, the hydrogen sensors 151 to 154 will be described. The hydrogen sensors 151 to 154 are respectively installed at positions P1, P2 on the upper part of the first fuel cell stack 118, position P3 on the upper part of the first hydrogen tank 120a, and position P4 on the upper part of the second hydrogen tank 120b. The hydrogen sensors 151 to 154 communicate with the FCECU136. Hereinafter, the hydrogen sensors 151 to 154 may be collectively referred to as the first sensor group.

[0120] As Figure 9 shown, the hydrogen sensors 151, 153, 154 among the hydrogen sensors 151 to 154 are connected to positions Q1, Q3, Q4 on the first communication bus CAN1. The hydrogen sensor 152 is connected to position R2 on the second communication bus CAN2. In addition, Figure 9 the illustration of the low-voltage battery 37 is omitted.

[0121] As Figure 10 shown, the connection states of the identification A pins and the identification B pins of the hydrogen sensors 151 to 154 are respectively set to GND / OPEN, OPEN / OPEN, OPEN / GND, GND / GND. In addition, the configuration structure (wiring structure) of the FCECU136 and the hydrogen sensors 151 to 154 is the same as that Figure 3 shown in the above-described embodiment, and thus its description is omitted.

[0122] Next, the hydrogen sensors 251 to 254 will be described. The hydrogen sensors 251 to 254 are respectively installed at positions P5, P6 on the upper part of the second fuel cell stack 218, position P7 on the upper part of the third hydrogen tank 220a, and position P8 on the upper part of the fourth hydrogen tank 220b. The hydrogen sensors 251 to 254 communicate with the FCECU236. Hereinafter, the hydrogen sensors 251 to 254 may be collectively referred to as the second sensor group.

[0123] As Figure 9As shown, the hydrogen sensors 251, 253, and 254 among the hydrogen sensors 251 to 254 are connected to positions R8, R6, and R5 of the second communication bus CAN2. The hydrogen sensor 252 is connected to position Q7 of the first communication bus CAN1.

[0124] As Figure 10 shown, the connection states of the identification A pins and the identification B pins of the hydrogen sensors 251 to 254 are set to GND / OPEN, OPEN / OPEN, OPEN / GND, and GND / GND, respectively. In addition, in the configuration structure (wiring structure) of the hydrogen sensors 151 to 154, if the correspondence between the communication bus to which the communication terminal is connected and the connection states of the identification A pin and the identification B pin is swapped, the configuration structure (wiring structure) of the FCECU 236 and the hydrogen sensors 251 to 254 is obtained. Therefore, the configuration structure (wiring structure) of the FCECU 236 and the hydrogen sensors 251 to 254 is omitted from the illustration.

[0125] In the hydrogen sensors (sensors) 151 to 154 and 251 to 254 according to this second modification, the control device (ECU) includes the FCECU 136 (first control device) that controls the first control object 130 and the FCECU 236 (second control device) that controls the second control object 230. Regarding the hydrogen sensors 151 to 154 and 251 to 254, the correspondence between the communication bus (first communication bus CAN1 or second communication bus CAN2) to which the communication terminal is connected and the connection states (GND or OPEN) of the identification A pin and the identification B pin (identification terminal) is swapped between the case of being included in the first sensor group that communicates with the FCECU 136 and the case of being included in the second sensor group that communicates with the FCECU 236.

[0126] According to such a structure, an identifier based on a standard format or an identifier based on an extended format is set for each of the hydrogen sensors 151 to 154 and 251 to 254. Accordingly, it is possible to simultaneously perform gas leakage detection of the hydrogen sensors 151 to 154 in the first sensor group and gas leakage detection of the hydrogen sensors 251 to 254 in the second sensor group to achieve redundancy.

[0127] For example, imagine a situation where among eight hydrogen sensors 151 to 154, 251 to 254, a fault such as a disconnection of the pin marked A occurs in hydrogen sensor 151. This hydrogen sensor 151 is responsible for detecting gas leakage in the first fuel cell stack 118. When a fault occurs in hydrogen sensor 151, the combination of the connection states of the pin marked A and the pin marked B of hydrogen sensor 151 is OPEN / OPEN. Hydrogen sensor 151 is connected to the first communication bus CAN1. Therefore, the identifier of the faulty hydrogen sensor 151 becomes the same CAN-ID_D as that of hydrogen sensor 252. Hydrogen sensor 252 is responsible for detecting gas leakage in the second fuel cell stack 218.

[0128] Therefore, FCECU136 uses the detection result of the non-faulty hydrogen sensor 152 installed at position P2 to detect gas leakage in the first fuel cell stack 118. FCECU236 only uses the detection result of hydrogen sensor 251 installed at position P5 to detect gas leakage in the second fuel cell stack 218. Accordingly, the sensor system 210 in the second modification example can continue gas leakage detection.

[0129] In addition, in the above-described embodiments and modification examples, the fuel cell vehicle 12 has been taken as an example for explanation. However, the moving body to which the sensors and the sensor system according to the present invention can be applied is not limited to the fuel cell vehicle 12. The sensors and the sensor system according to the present invention can also be applied to moving bodies such as four-wheel vehicles, two-wheel vehicles, airplanes, drones, ships, and trains driven by internal combustion engines or secondary batteries.

[0130] Furthermore, in the above-described embodiments and modification examples, identifiers are set in different formats (standard format or extended format) according to the communication buses to which the sensors are connected. However, sometimes, even if identifiers are set in the same format (for example, the standard format) for multiple sensors connected to the first communication bus CAN1 and multiple sensors connected to the second communication bus CAN2, it is possible to prevent confusion of the identifiers.

[0131] For example, two sensors are connected to the first communication bus CAN1. The identification terminals (pin marked A and pin marked B) of these two sensors are set to GND / OPEN and OPEN / GND, respectively. For these two sensors, identifiers are set in the standard format. Two new sensors are connected to the second communication bus CAN2. The identification terminals of these two sensors are also set to GND / OPEN and OPEN / GND, respectively. For these two sensors, identifiers are also set in the standard format. In this case, even if a 1-bit fault occurs in any of the sensors, it is possible to prevent confusion of the identifiers.

[0132] In addition, the present invention is not limited to the above-described embodiments, and various structures can be adopted without departing from the gist of the present invention.

Claims

1. A sensor is connected to a control device via any one of two communication buses built on a moving body and is identified by an inherent identifier. Characterized in that it has a communication terminal, a plurality of identification terminals, and an identifier setting unit, wherein the communication terminal is connected to one of the two communication buses or the other communication bus and communicates with the control device; the plurality of identification terminals are set to be in any one of a connection state of an open circuit state not connected to any potential and a grounded state connected to a ground potential; the identifier setting unit sets the identifier of the sensor according to the connection state of the plurality of identification terminals and the difference in the communication bus to which the communication terminal is connected; the identifier setting unit sets the identifier in different modes according to whether the communication bus connected to the communication terminal is the one communication bus or the other communication bus; the control device is composed of a first control device and a second control device, wherein the first control device controls a first controlled object and the second control device controls a second controlled object; when the sensor is included in a first sensor group that communicates with the first control device and when the sensor is included in a second sensor group that communicates with the second control device, the correspondence between the communication bus to which the communication terminal is connected and the connection state of the identification terminal is swapped.

2. The sensor according to claim 1, characterized in that the identification terminal is composed of a first terminal and a second terminal; when either one of the first terminal and the second terminal is set to the grounded state, the communication terminal is connected to the one communication bus; when both the first terminal and the second terminal are set to the open circuit state, the communication terminal is connected to the other communication bus.

3. A sensor system, characterized in that it has a plurality of sensors according to claim 2; the plurality of sensors are composed of a first gas sensor and a second gas sensor, wherein the first gas sensor detects a gas leaking from a fuel cell stack, and the second gas sensor detects the gas leaking from the fuel cell stack; either one of the first terminal and the second terminal of the first gas sensor is set to the grounded state; both the first terminal and the second terminal of the second gas sensor are set to the open circuit state.

Images