JP2010195133A - Onboard device control system and identifier setting method in onboard device control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an onboard device control system with excellent versatility, preventing wrong attachment of a slave device. <P>SOLUTION: The slave device 200 is connected to a signal line 13 of a bus 10 by daisy chain connection, a resistor 201 is connected between the signal lines 13 in series, and a switch means 202 is connected to the resistor 201 in parallel. One end of the signal line of the bus 10 is connected to a master device 100, and the other end is terminated at the resistor 15. When setting an identifier, the switch means 202 is opened in each slave device 200, and the master device 100 applies a D.C. voltage to the signal line 13. Each slave device 200 detects the potential of one end of the resistor 15, and sets an identifier corresponding to the potential as its own identifier. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an in-vehicle device control system in which a master device and a slave device are connected by a bus.

  In an in-vehicle device control system, an in-vehicle LAN is installed in a vehicle, and a large number of electronic control units (ECUs) are connected to the in-vehicle LAN. Here, the ECU corresponds to a node connected to the in-vehicle LAN, and includes a node to which an in-vehicle device to be controlled is connected. For example, in-vehicle LAN standards include CAN (Controller Area Network) and LIN (Local Interconnect Network). In the LIN standard, a single master system is adopted, and one ECU operates as a master device, and the other ECU operates as a slave device. Usually, an ECU that operates as a master device (hereinafter simply referred to as “master device”) includes a communication interface circuit with a bus and a control circuit including a microcomputer, a memory, and the like. An ECU that operates as a slave device (hereinafter simply referred to as a “slave device”) includes a communication interface circuit with a bus, a control circuit for an in-vehicle device, and an interface circuit for the in-vehicle device or sensor. .

  An identifier is determined in advance for each slave device, and the header of the communication message from the master device to the slave device includes the identifier of the slave device. The identifier and each slave device do not necessarily have a one-to-one relationship, and the identifier may be used as a kind of command by assigning a plurality of identifiers to one slave device.

  The memory of the master device stores parameters necessary for controlling the in-vehicle device connected to the slave device and the identifier of each slave device. The control circuit of the master device controls the in-vehicle device based on the identifier and parameter (see Patent Document 1). For example, the case of controlling an actuator that opens and closes a damper of an air conditioner will be described. A potentiometer is attached to the actuator as a sensor for detecting a rotation angle. The potentiometer value when the damper is opened and closed is stored in the memory of the master device. The master device instructs the operation of the actuator by transmitting the potentiometer value to the slave device. The slave device feedback-controls the actuator so that the detected value of the potentiometer becomes the value received from the master device.

JP 2005-335607 A

  By the way, the standard such as LIN described above simplifies the system from the viewpoint of cost and the like, and the identifiers assigned to the respective slave devices are fixedly set in advance. Similarly, in the master device, the identifier of each slave device is fixedly set. For this reason, when multiple slave devices of the same type are connected by a bus, or when the same type of slave device is used between a plurality of systems, the identifiers differ even though the hardware configuration of the slave devices is common. Therefore, it was necessary to manufacture and manage each as a different slave device. As a result, the slave device lacks versatility, and there is a risk that an incorrect slave device may be attached during assembly work.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an in-vehicle device control system that is highly versatile and can prevent erroneous attachment of a slave device. .

  To achieve the above object, the present invention comprises a master device installed in a vehicle and one or a plurality of slave devices connected to the master device, and a single master system is provided between the master device and the slave device. In the in-vehicle device control system that performs communication, the master device is connected to one end of the bus, the other end is grounded, and the slave device is daisy chain connected to the bus between the master device and the ground. The apparatus includes switch means for electrically short-circuiting or opening a pair of buses, impedance elements connected in parallel to the switch means, means for detecting the potential of at least one end of the impedance means, and communication control means, In the identifier setting mode, the communication control means of the slave device is inserted by the detection means with the switch means opened. The potential of at least one end of the inductance element is detected, and after the detection process, the switch means is short-circuited, and an identifier corresponding to the detected potential is set as its own identifier, and the communication control means of the master device is in the identifier setting mode. A predetermined DC voltage is applied to the bus.

  According to the present invention, in the identifier setting mode, the bus is in a state where impedance elements are connected in series by the number of slave devices. Since one end of the bus is applied with a predetermined DC voltage by the master device and the other end is grounded, one end of the impedance element in each slave device is connected to the DC supplied from the master device. The voltage becomes a divided potential. Accordingly, since each slave device can recognize from the potential how many times it is connected to the bus from the master device side, an identifier corresponding to the potential can be set. As described above, each slave device recognizes the position on the bus and automatically sets the identifier, so that the slave device before assembly can be generalized and the assembly workability is improved.

  As an example of a more specific method for setting the corresponding identifier from the detection potential, the communication control unit of the slave device includes a storage unit that stores a correspondence relationship between the detection potential and the identifier, and is stored in the storage unit. For example, the identifier is obtained from the detected potential with reference to the correspondence relationship. The correspondence relationship between the detected potential and the identifier varies depending on the number of slave devices connected to the bus. Therefore, the storage means of the slave device stores the correspondence relationship between the detected potential and the identifier for each number of slaves connected to the bus, and the communication control means of the master device slaves after the application of the predetermined DC voltage to the bus is completed. Notifying the number of slave devices connected to the bus to the device, the communication control means of the slave device refers to the correspondence stored in the storage means, the number of slave devices received from the master device and the detection potential If the identifier is obtained from the identifier, the identifier can be surely obtained.

  As another specific example of setting the corresponding identifier from the detected potential, the communication control means of the master device is connected to the slave device after the application of the predetermined DC voltage to the bus. The communication control means of the slave device calculates the identifier from the detected potential based on the value of a predetermined DC voltage applied to the bus by the master device and the number of slave devices received from the master device. Can be mentioned.

  Note that the notification of the number of slave devices from the master device to the slave devices may be performed using an identifier common to all slave devices. Moreover, as a communication standard between the master device and the slave device, for example, LIN (Local Interconnect Network) can be cited.

  As described above, according to the present invention, each slave device recognizes the position on the bus and automatically sets an identifier, so that the slave device before assembly can be generalized and assembled. Also improves.

Configuration diagram of in-vehicle device control system Master unit configuration diagram Configuration diagram of slave layer device Configuration diagram of interior air conditioning system The figure explaining an example of an identifier list The figure explaining an example of an identifier table Flow chart explaining operation of master device Flow chart explaining operation of slave device Flow chart explaining operation of slave device Sequence chart explaining initial operation of in-vehicle device control system The flowchart explaining the identifier calculation method of the slave apparatus concerning another example

  An in-vehicle device control system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an in-vehicle device control system. In the present embodiment, a control system for an in-vehicle air conditioning system will be described as an example.

  In this in-vehicle device control system, as shown in FIG. 1, a plurality of ECUs are connected to a bus 10 in an in-vehicle LAN. In this embodiment, LIN is adopted as a standard for the in-vehicle LAN. Therefore, only one ECU operates as a master, and the other ECUs operate as slaves. In the present embodiment, master device 100 and a plurality of slave devices 200 are connected to bus 10 of the in-vehicle LAN. As will be described later, for example, an actuator for opening and closing a damper is connected to the slave device 200. The master device 100 controls the operation of the actuator connected to each slave device 200.

  In the present embodiment, as described above, LIN is adopted as the standard of the in-vehicle LAN, so that the bus 10 includes a power supply line 11, a ground line 12, and a signal line 13. A characteristic point of the present invention is that, as shown in FIG. 1, the physical connection form between each slave device 200 and the signal line 13 is not a bus connection but a daisy chain connection. As will be described later, in the slave device 200, the connection to the signal line 13 is switched between the bus connection and the daisy chain connection depending on the situation. As shown in FIG. 1, the physical connection form between each slave device 200 and the power supply line 11 and the ground line 12 is bus connection, but may be daisy chain connection. One end of the bus 10 is connected to the master device 100. At the other end of the bus 10, the power line 11 and the ground line 12 are open. On the other hand, the signal line 13 is grounded via a resistor 15 which is an impedance element. In other words, the signal line 13 of the bus 10 is terminated by the termination resistor.

  As shown in FIG. 2, the master device 100 includes a transceiver 101 for connection to the signal line 13 of the in-vehicle LAN bus 10 and a control circuit 110 for controlling the actuator connected to each slave device 200. ing. The control circuit 110 includes a main arithmetic unit 111, a ROM 112 that is a nonvolatile storage unit, and a RAM 115 that is a volatile storage unit. The ROM 112 stores a control program 113 and an identifier list 114 of each slave device 200. The control circuit 110 operates by executing a control program 113 stored in the ROM 112. Details of the identifier list 114 will be described later. Further, the master device 100 applies a DC power source 120 between the power line 11 and the ground line 12 of the bus 10. In FIG. 2, an example in which a power source is built in the master device 100 is illustrated for simplicity of explanation, but a mode in which power supplied from a vehicle is supplied to the bus 10 may be used.

  As shown in FIG. 3, the slave device 200 includes a resistor 201 that is an impedance element connected in series to the signal line 13 of the bus 10, and a relay switch 202 connected in parallel to the resistor 201. Here, the resistance value of the resistor 201 is set to the same value as that of the terminating resistor 15 of the signal line 13 from the viewpoint of easy calculation and design. The slave device 200 includes a communication transceiver 203 connected to one end of the resistor 201, a communication control unit 204 that controls communication with the master device 100, an actuator control circuit 207, and the actuator 208 described above. A potentiometer 209 for detecting the rotation angle of the actuator 208 and a voltage detection means 210 for detecting the potential at one end of the resistor 201 with reference to the ground. The relay switch 202 can be controlled by the communication control unit 204.

  The communication control unit 204 includes an identifier table 205 referred to in an identifier setting mode, which will be described later, and a self-identifier storage unit 206 that stores its own identifier. Details of the identifier table 205 will be described later. The self identifier storage unit 206 does not store its own identifier before assembly, and is registered by processing in the identifier setting mode. In the identifier setting mode, it is necessary to receive a communication message from the master device 100. For this reason, the communication control unit 204 not only processes a communication message from the master device 100 addressed to the identifier stored in the self-identifier storage unit 206 but also addresses a specific identifier common to all slave devices 200 before assembly. It also handles communication messages. The former communication message relates to the control of the actuator 208, and the latter relates to the registration processing of the identifier in the self-identifier storage unit 206. In other words, the communication control unit 204 performs a communication process using a specific identifier common to all the slave devices 200 even when the identifier is not assigned.

  The actuator control circuit 207 drives and controls the actuator 208 so that the resistance value (detected value) of the potentiometer 209 becomes a target value included in the operation instruction from the master device 100.

  Next, an example of the configuration of the in-vehicle device controlled by the slave device 200 will be described with reference to FIG. In the present embodiment, as shown in FIG. 4, the air conditioner main body 300 is formed with an outside air inlet 301 and an inside air inlet 302, and outside air is provided at the junction of the outside air inlet 301 and the inside air inlet 302. An intake damper 303 for adjusting the inflow rate of the inside air is rotatably attached. A fan 304 is disposed downstream of the damper 303. The fan 304 sucks outside air or inside air from the outside air inlet 301 or the inside air inlet 302. An evaporator 305 is provided downstream of the fan 304. The evaporator 305 is a device constituting a refrigeration cycle, and is connected to a compressor or the like (not shown). Further, a heater 306 is provided downstream of the evaporator 305, and a heater damper 307 for adjusting the amount of air flowing into the heater is rotatably provided on the evaporator 305 side of the heater 306. . Further, the air conditioner body 300 is formed with a differential outlet 308, a vent outlet 309, and a foot outlet 310. In each of the air outlets 308, 309, and 310, a differential air outlet damper 311, a vent air outlet damper 312 and a foot air outlet damper 313 are rotatably provided.

  Each of the slave devices 200 performs drive control of one damper. That is, one slave device 200 is provided corresponding to each damper. Each of the dampers 303, 307, 311, 312, and 313 is connected to the actuator 208 of the slave device 200 via a link mechanism (not shown).

  Next, the identifier list 114 stored in the master device 100 will be described with reference to FIG. The “Description” column of the identifier list 114 in FIG. 5 explains the meaning of each identifier, and the identifier list 114 actually stored in the ROM 112 is only the “Identifier” column.

  As shown in FIG. 5, each slave device 200 is assigned an identifier for transmitting an operation request and an identifier for transmitting a status request. The identifier for status request transmission is the next value of the identifier for operation request transmission. Further, the identifier list 114 is stored in advance in a predetermined order depending on the type of use of the slave device 200. In the example of FIG. 5, there are a slave device for intake damper control, a slave device for differential outlet damper control, a slave device for vent outlet damper control, and so on. The identifier list 114 is assigned a specific identifier common to the slave devices 200. In the example of FIG. 5, an identifier registration request transmission identifier (0x3A) and a status request transmission identifier (0x3B). As described above, the communication message addressed to the identifier can be received by all the slave devices 200. That is, the specific identifier common to the slave devices 200 is used for communication between the slave device 200 to which the identifier is not assigned and the master device 100.

  Next, the identifier table 205 stored in the slave device 200 will be described with reference to FIG. The identifier table 205 is a list describing the correspondence between the voltage detected by the voltage detecting means 210 and the identifier. The correspondence between the voltage and the identifier depends on the number of slave devices 200 connected to the bus 10. As will be described later, the voltage detection by the voltage detection means 210 is performed when all the slave devices 200 are connected to the bus 10 and the relay switch 202 of each slave device 200 is off. At this time, the signal line 13 between the master device 100 and the ground is in a state in which the resistor 201 and the terminating resistor 15 of each slave device 200 are connected in series. Therefore, the voltage detected by the voltage detection unit 210 is a value obtained by dividing the DC voltage applied to the signal line 13 by the master device 100 by the resistor 201 and the terminating resistor 15 of the slave device 200. This value varies depending on the order of the slave device 200 as viewed from the master device 100, and also varies depending on the number of slave devices 200. Therefore, as shown in FIG. 6, the identifier table 205 describes the correspondence between the voltage and the identifier for each slave device 200. In the example of FIG. 6, the voltage has a width of ± 5% in consideration of the fluctuation of the voltage applied to the signal line 13 in the master device 100.

  As described above, each slave device 200 uses two identifiers for operation request and status request, but both identifiers take adjacent values. Therefore, in the example of FIG. 6, only one identifier corresponding to each voltage is described, and the description of the other identifier is omitted.

  Next, an assembly process of the in-vehicle device control system according to the present embodiment will be described. The process is started when the master device 100 is turned on with the master device 100 and all the slave devices 200 and the terminating resistor 15 connected to the bus 10.

  First, the operation of the master device 100 will be described with reference to FIG. FIG. 7 is a flowchart for explaining the operation of the master device. The control circuit 110 of the master device 100 operates as an identifier setting mode when the vehicle-mounted device control system is first activated (when power is turned on). Specifically, the control circuit 110 of the master device 100 first applies a DC voltage by maintaining the signal line 13 at a high level for a predetermined time (step SM1). In this embodiment, since the LIN standard is adopted, the voltage value is the voltage value of the power supply voltage (battery voltage). The control circuit 110 of the master device 100 is common to the slave devices 200, and the number of slave devices 200 connected to the bus 10 for the identifier for transmitting the operation request for the identifier (0x3A in the example of FIG. 5). Is transmitted (step SM2). The number of slave devices 200 can be acquired by referring to the identifier list 114 shown in FIG. By this notification of the number of slave devices 200, each slave device 200 completes the identifier setting process. Next, the control circuit 110 of the master device 100 refers to the identifier list 114, transmits a status request to each slave device 200 using an individual identifier, and confirms that there is a response from each slave device 200. (Steps SM3-6). When the control circuit 110 of the master device 100 confirms responses from all the slave devices 200, the control circuit 110 shifts to the normal mode and starts control processing of the slave device 200 (steps SM7 and SM8). On the other hand, if there is no response from the slave device 200, the process returns to step SM2 and is retried. The control process in step SM8 is a conventionally known process, and communicates with the slave device 200 using the operation request transmission identifier and the status request transmission identifier assigned to the slave device 200.

  Next, the operation of the slave device will be described with reference to FIGS. FIG. 8 is a flowchart for explaining the operation of the slave device in the identifier setting mode, and FIG. 9 is a flowchart for explaining the operation of the slave device in the normal mode.

  The communication control unit 204 of the slave device 200 starts operating when DC power is supplied from the master device 100 via the bus 10. First, as shown in FIG. 8, the communication control unit 204 determines whether or not its own identifier has already been registered in the self-identifier storage unit 206 (step SS1), and if already registered, shifts to the normal mode standby state. To do. On the other hand, when it is not registered, it operates as an identifier setting mode. In the identifier setting mode, first, the communication control unit 204 controls the relay switch 202 to be turned off (step SS2). As a result, the signal line of the bus 10 is in a state in which the plurality of resistors 201 and the resistor 15 are connected in series. Next, the potential of the signal line 13 with respect to the ground is acquired by the voltage detection unit 210, and the voltage value is stored in a predetermined storage unit (step SS3). Next, the communication control unit 204 controls the relay switch 202 to be turned on after a predetermined time has elapsed (steps SS4 and SS5). As a result, the resistor 201 is short-circuited, so that the signal line of the bus 10 can communicate according to the LIN standard. The predetermined time until the relay switch 202 is turned on is set to be longer than at least the DC voltage application time to the signal line 13 by the master device 100.

  Next, the communication control unit 204 receives from the master device 100 a communication message that is common to each slave device 200 and is addressed to the identifier for transmitting the operation request for the identifier (0x3A in the example of FIG. 5) (step SS6). The communication message includes the number of slave devices 200 connected to the bus 10. Next, the communication control unit 204 acquires an identifier from the identifier table 205 based on the number of slave devices 200 received from the master device 100 and the voltage value detected and stored in step SS3, and the identifier is stored in the self-identifier storage unit. It memorize | stores in 206 (step SS7). In the present embodiment, each slave device 200 uses two identifiers, but the identifier acquired from the identifier table 205 is one. On the other hand, since the two identifiers have consecutive values, the communication control unit 204 stores the identifier acquired from the identifier table 205 and the value consecutive to the identifier in the self-identifier storage unit 206 as the other identifier. As a result of the above processing, the slave device 200 is set with its own identifier, so that it shifts from the identifier setting mode to the standby mode of the normal mode.

  As illustrated in FIG. 9, when the communication control unit 204 of the slave device 200 receives a communication message addressed to its own identifier from the master device 100 in the standby state, the communication message is stored in the self-identifier storage unit 206. When addressed to an identifier, the respective processing is performed. Specifically, in the case of a communication message addressed to an identifier for operation request transmission, the communication control unit 204 sends the operation request to the actuator control circuit 207 to drive and control the actuator 208 (step SS11). The actuator control circuit 207 feedback-controls the actuator 208 so that the detected value of the potentiometer 209 becomes the target value received from the master device 100. On the other hand, in the case of a communication message addressed to an identifier for status request transmission, the communication control unit 204 informs the master device 100 that the actuator control circuit 207 is “driving” when the actuator 208 is in the drive control. In response, if the actuator 208 is stopped, it responds to the master device 100 that it is “stopped” (steps SS21, S22, S23).

  Next, the initial operation of the entire in-vehicle device control system according to the present embodiment will be described with reference to FIG. FIG. 10 is a sequence chart for explaining the initial operation of the in-vehicle device control system. Here, a case where the vehicle-mounted device control system is activated for the first time will be described. In the initial state, it is assumed that the master device 100 and the slave device 200 are connected to the bus 10 of the in-vehicle LAN.

  The control circuit 110 of the master apparatus 100 first applies a DC voltage to the signal line 13 for a predetermined time by turning on the signal line 13. In FIG. 10, this period is represented by a hatched line with a symbol SA1. When the master device 100 is activated, power is supplied to the slave device 200 via the power line 11 and the ground line 12, and the operation starts. The communication control unit 204 of the slave device 200 measures the voltage between one end of the resistor 201 and the ground with the relay switch 202 turned off, and stores the voltage value in a predetermined storage unit (step SA2). The control circuit 110 of the master device 100 stops applying the voltage to the signal line 13 after a predetermined time elapses, while the communication control unit 204 of the slave device 200 turns on the relay switch 202 to short-circuit the resistor 201 after the predetermined time elapses. . As a result, the bus 10 becomes communicable.

  Next, the control circuit 110 of the master device 100 notifies the number of slave devices 200 to the identifier for operation request transmission that is common to the slave devices 200 (step SA3). This notification is received by all the slave devices 200 connected to the bus 10. Upon receipt of the notification, the communication control unit 204 of each slave device 200 acquires an identifier from the identifier table 205 based on the number of slave devices 200 and the voltage value detected in step SA2, and a self-identifier storage unit It memorize | stores in 206 (step SA4). Next, the control circuit 110 of the master device 100 transmits a status request to each slave device 200 (step SA5). The transmission of the status request uses an identifier for individually identifying each slave device 200 stored in the identifier list 114. Each slave device 200 responds to the status request from the master device 100 (step SA6). When the control circuit 110 of the master device 100 confirms responses from all the slave devices 200, it shifts to the normal mode.

  When the master device 100 and the slave device 200 are connected to the in-vehicle LAN bus 10 and the system is activated by the above processing, an identifier is automatically set for each slave device 200. The identifier set for each slave device 200 is determined by the voltage detected by the resistor 201, and the voltage value depends on what number the slave device 200 is connected to when counted from the master device 100. On the other hand, in the master device 100, the identifier corresponding to the slave device 200 is determined in advance by the identifier list 114. Therefore, each slave device 200 needs to be connected to the bus 10 at a position defined by the identifier list 114 and the identifier table 205 (in order from the master device 100). However, since the physical position of the slave device 200 is usually uniquely determined by the shape of the assembly destination such as the air conditioner main body 300, the assembly workability is not significantly affected.

  As described above, according to the in-vehicle device control system according to the present embodiment, the identifier of each slave device 200 is automatically given at the time of assembly work, so that the slave device 200 before assembly can be generalized.

  Although one embodiment of the present invention has been described in detail above, the present invention is not limited to this. For example, in the above embodiment, the identifier is acquired from the identifier table 205 based on the voltage between the signal line 13 and the ground detected by the voltage detection unit 210. However, the DC voltage applied to the signal line 13 may fluctuate. For example, in an in-vehicle device control system, power is supplied by a battery, so that the power supply voltage may be lower than a predetermined reference voltage depending on the connected battery. On the other hand, the voltage value stored in the identifier table 205 is based on the premise that the DC voltage applied to the signal line 13 is a predetermined reference voltage. For this reason, when the number of slave devices 200 connected to the bus 10 is large, it is conceivable that an appropriate identifier cannot be acquired if the DC voltage applied to the signal line 13 is significantly reduced. Therefore, it is preferable that the voltage detection unit 210 detects the voltage between the power supply line 11 and the ground and corrects the detection voltage of the signal line 13. Specifically, the detection voltage value of the signal line 13 may be corrected by multiplying by (predetermined reference voltage value / voltage value of the power supply line 11), and the identifier table 205 may be referred to based on the correction value.

  In the above-described embodiment, the identifier table 205 describing the correspondence between the voltage value and the identifier is stored in advance in the slave device 200, and the identifier is set by referring to the identifier table 205. In such a method, the identifier corresponding to the voltage value can be arbitrarily set, so that the degree of freedom of setting is high. On the other hand, when the correspondence relationship between the voltage value and the identifier is determined by a predetermined rule, it is also possible to calculate the identifier from the measured voltage value according to the rule. For example, there is a rule that “identifiers are assigned two by two in order from the closest to the master device 100”. An identifier calculation process in this case will be described with reference to the flowchart of FIG.

  The communication control unit 204 of the slave device 200 calculates a theoretical voltage value detected by the slave device 200 connected to the bus 10 in order from the master device 100. Specifically, the communication control unit 204 represents the position from the master device 100 as a variable N, and loops the variable N while increasing the variable N by 1 from 0 to the number of slaves −1 (steps SS31 to SS34). Then, the communication control unit 204 sets the center value of theoretical voltage values detected by the slave device 200 as “reference voltage applied by the master device 100 to the signal line 13 * (number of slaves−N) / (number of slaves + 1)”. (Step SS32). “+1” is because there is a resistor 15 that terminates the signal line 13. When the voltage value detected by the voltage detection unit 210 is within a predetermined range (for example, ± 5%) centered on the center voltage value (step SS33), the communication control unit 204 sets the operation request identifier as a variable. The value of N * 2 and the identifier for status request are set and stored as the value of variable N * 2 + 1 (step SS36). If the identifier cannot be calculated by the above process, a predetermined error process is performed (step SS35). In step SS33, the voltage value detected by the voltage detection unit 210 is used as it is. However, it is preferable that correction is performed by the detected voltage value of the power supply line 11 as described above. In this way, the slave device 200 does not need to hold the identifier table 205 by this method.

  In the above embodiment, the master device 100 controls the transceiver 101 so as to output a high level as a method of applying a DC voltage to the signal line 13. Alternatively, a direct current voltage may be applied directly to the signal line 13.

  Moreover, in the said embodiment, although the relay switch was used as a switch means which short-circuits the resistor 201 in the slave apparatus 200, you may use another means. For example, semiconductor elements such as bipolar transistors, field effect transistors, and diodes may be used.

  In the above embodiment, identifiers assigned to the slave devices 200 are stored in the ROM 112 of the master device 100 as the identifier list 114. However, the identifiers may be stored in a form embedded in the control program 113.

  In the above embodiment, two identifiers are assigned to each slave device 200, but may be one or three or more depending on the type of the slave device 200.

  In the above-described embodiment, the drive control of the actuator 205 that performs the rotational motion is illustrated, but the present invention can be implemented even with other devices.

  Moreover, although the application example in the vehicle interior air conditioning system has been described in the above embodiment, the present invention can be applied to other systems such as a power window and a mirror control system.

  DESCRIPTION OF SYMBOLS 10 ... Bus, 11 ... Power supply line, 12 ... Ground line, 13 ... Signal line, 100 ... Master device, 110 ... Control circuit, 112 ... ROM, 113 ... Control program, 114 ... Identifier list, 200 ... Slave device, 201 ... Resistor 202 ... Relay switch 204 ... Communication control unit 205 ... Identifier table 206 ... Self-identifier storage unit 207 ... Actuator control circuit 208 ... Actuator 209 ... Potentiometer 210 ... Voltage detection means 300 ... Air conditioning apparatus main body 301 ... Outside air intake port 302 ... Inside air intake port 303 ... Intake air intake damper 304 ... Fan 305 ... Evaporator 306 ... Heater Air outlet, 310 ... Foot air outlet, 311 ... Differential air outlet damper, 312 ... Vent air outlet damper , 313 ... foot outlet damper.

Claims (7)

In a vehicle-mounted device control system that includes a master device installed in a vehicle and one or more slave devices connected to the master device, and performs single master communication between the master device and the slave device.
Connect the master device to one end of the bus and ground the other end to the ground, daisy chain the slave device to the bus between the master device and the ground,
The slave device includes switch means for electrically short-circuiting or opening a pair of buses, an impedance element connected in parallel to the switch means, means for detecting the potential of at least one end of the impedance means, and communication control means. ,
In the identifier setting mode, the communication control means of the slave device detects the potential of at least one end of the impedance element by the detection means in a state where the switch means is opened, and shorts the switch means after the detection processing to obtain the detected potential. Set the corresponding identifier as its own identifier,
The communication control means of the master device applies a predetermined DC voltage to the bus in the identifier setting mode. The communication control means of the slave device comprises storage means for storing the correspondence relationship between the detection potential and the identifier, and acquires the identifier from the detection potential with reference to the correspondence relationship stored in the storage means. Item 1. The vehicle equipment control system according to Item 1. The storage means of the slave device stores the correspondence between the detected potential and the identifier for each number of slaves connected to the bus,
The communication control means of the master device notifies the slave device of the number of slave devices connected to the bus after completing the application of the predetermined DC voltage to the bus,
The in-vehicle device according to claim 2, wherein the communication control means of the slave device acquires the identifier from the number of slave devices and the detected potential received from the master device with reference to the correspondence relationship stored in the storage means. Control system. The communication control means of the master device notifies the slave device of the number of slave devices connected to the bus after completing the application of the predetermined DC voltage to the bus,
The communication control means of the slave device calculates the identifier from the detected potential based on a value of a predetermined DC voltage applied to the bus by the master device and the number of slave devices received from the master device. In-vehicle device control system. The in-vehicle device control system according to claim 3 or 4, wherein the notification of the number of slave devices from the master device to the slave devices is performed using an identifier common to all slave devices. The in-vehicle device control system according to any one of claims 1 to 5, wherein LIN (Local Interconnect Network) is used as a communication standard between a master device and a slave device. A slave device in an in-vehicle device control system that includes a master device installed in a vehicle and one or more slave devices connected to the master device, and performs single-master communication between the master device and the slave device. A method for setting an identifier,
Connect the master device to one end of the bus and ground the other end to the ground, daisy chain the slave device to the bus between the master device and the ground,
The slave device includes switch means for electrically short-circuiting or opening a pair of buses, an impedance element connected in parallel to the switch means, means for detecting the potential of at least one end of the impedance means, and communication control means. ,
At the time of setting the identifier of the slave device, the communication control means of the master device applies a predetermined DC voltage to the bus in the identifier setting mode, and the communication control means of the slave device is connected to the impedance by the detecting means with the switch means opened. An identifier setting method in an in-vehicle device control system, wherein the potential of at least one end of the element is detected, the switch means is short-circuited after the detection process, and an identifier corresponding to the detected potential is set as its own identifier.

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