JPH0795740B2 - Vehicle communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a vehicular communication device, and more particularly to a vehicular communication device for improving reliability in communication.

(Prior Art) In recent years, in-vehicle electronics have been promoted. With the progress of such electronics, the number of connection lines between a large number of terminal devices and the respective operating parts for operating them, that is, the wire harness, increases,
Due to the increase in the wire harness, the weight of the whole is increased and the reliability of the device is lowered.

Therefore, in recent years, various so-called multiplex communication systems have been developed, which can transmit information related to the operation of a large number of operation units through a small number of connection lines.

In such a conventional multiplex communication system, a transmission circuit for transmitting information related to the operation of each operation unit provided corresponding to a plurality of terminal devices, and information related to the operation transmitted from this transmission circuit. And a drive circuit for driving the corresponding terminal device according to the content of the information received by the reception circuit. In addition, in the conventional multiplex communication system, by adding a parity bit when transmitting information related to the operation of the operation unit and executing a so-called parity check,
We are trying to improve the reliability of communication.

When transmitting or receiving information related to the operation of such an operation unit, for example, when the connection line is broken or when the information changes due to electromagnetic noise or the like, perform the above-mentioned parity check or the like. By so doing, so-called communication error is detected.

(Problems to be solved by the invention) By the way, when the ignition switch is turned on,
That is, when the key cylinder is rotated from the ON position to the start position to start the engine, the power supply to the car radio is cut off to reduce the power consumption at the engine start.

On the other hand, terminal devices that require urgency, such as headlamps, can be turned on even when the engine is started.

The vehicle communication device needs to control such a headlamp as well, performs communication operation between the master station and the slave station regardless of the position of the ignition switch, and transmits from the slave station having the headlamp switch. When the information is collected, the control information is transmitted to the slave station having the headlamp according to the collected information so that the headlamp is turned on or off.

However, when starting the engine to operate the starter, a large current consumption flows, so that the power supply voltage of the battery may decrease. If communication is performed in such a state that the power supply voltage is lowered, malfunction may occur.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicular communication device configured to improve the reliability of communication.

[Structure of the Invention] (Means for Solving the Problem) As shown in FIG. 1, the means provided by the present invention for achieving the above object is to sequentially call the slave stations 2 to operate the operation section. A master station 1 that receives related information and transmits a drive signal of a terminal unit based on the information, and a master station 1 that transmits information related to the operation of an operation unit that operates the terminal unit to the master station 1 and A plurality of slave stations 2 that drive the terminal unit based on the received drive signals, and a multiplex transmission line 3 that electrically connects the master station 1 and the slave stations 2. In the vehicular communication device, in the master station 1, a detecting means 4 for detecting whether or not the position of the ignition switch is at the start position, and when the detecting means 4 detects the start position, the slave station 2 Temporary reception from If the start position is no longer detected by the stop means 5 for stopping and the detecting means 4, the information related to the operation of the operation section which is temporarily stopped and is being received is discarded, and the same slave station is called again to operate the operation section. And a communication control means 6 for receiving information relating to the operation of.

(Operation) In the present invention, when the master station 1 and the plurality of slave stations 2 are electrically connected by the multiplex transmission line 3 and the detection means 4 detects the start position of the ignition switch, the stop means 5 The reception from the slave station 2 is temporarily stopped. On the other hand, when the start position of the ignition switch is no longer detected by the detection means 4, the communication control means 6 discards the information related to the operation of the temporarily stopped operation section and calls the same slave station again. Since the information related to the operation of the operation unit is received, the information during communication cannot be read because the power supply voltage drops when the engine is started.Therefore, when communication is stopped and the engine is started and the power supply voltage is restored. , The reliability of the communication content can be improved by discarding the information being communicated and calling the same slave station again to receive the information.

(Example) Hereinafter, one example according to the present invention will be described in detail with reference to the drawings.

First, with reference to FIG. 2, an overall configuration of a vehicle communication device according to the present invention will be described.

A plurality of slave stations 100, 200, 300, 400, 500, 550, via the multiple transmission line LL, to the master station 10 arranged near the driver's seat of the vehicle,
Each of 600, ..., 900 is connected.

The master station 10 polls a plurality of slave stations, based on the communication section 11 for communicating with each slave station and the information related to the operation of the operation section collected via the multiplex transmission line LL. Logic unit 12 for controlling the corresponding terminal device
It consists of and.

The logic unit 12 is connected to an ignition switch 13, and has a detection means for detecting an ON operation of the ignition switch 13.

A child station 100 is arranged near the driver's seat of the vehicle. This slave station 100 is a communication unit 101 for communicating with the master station 10.
And a plurality of operation units. Explaining in detail the multiple operation parts, a small lamp switch for turning on or off the lamp for lighting the meter etc.
102, a headlamp switch 103 for turning off or turning on the headlamp, a turn signal switch 104 for indicating a left turn or a right turn, a hazard switch 105 for indicating that the vehicle is parked, and a horn. A large number of switch units such as the switch 106 are connected to the communication unit 101.

A child station 200 is arranged near the driver's seat of the vehicle. This slave station 200 is a communication unit 201 for communicating with the master station 10.
And a plurality of operation units. More specifically, a plurality of operation units will be described. A switch 205 for driving the windshield on the passenger side, a switch 206 for driving the windshield on the right side of the rear seat, and a switch 206 for driving the windshield on the left side of the rear seat. A large number of switch units such as a switch 207 and a door lock switch 208 are connected to the communication unit 201.

A child station 300 is provided on the front left side of the vehicle. The slave station 300 has a communication unit 301 for communicating with the master station 10,
It is composed of a plurality of terminal devices. That is, a small lamp 302 provided on the front left side of the vehicle, a head lamp 303, a turn signal lamp 304, and a horn 305.
Are connected to the communication unit 301.

A child station 400 is provided on the front right side of the vehicle. This child station 400, a communication unit 401 for communicating with the parent station 10,
It is composed of a plurality of terminal devices provided on the front right side of the vehicle. That is, each of the small lamp 402, the head lamp 403, the turn signal lamp 404, and the horn 405 is connected to the communication unit 401.

A slave station 500 is arranged at a door provided on the passenger side of the vehicle. The slave station 500 includes a communication unit 501 for communicating with the master station 10, a plurality of terminal devices provided on the door on the passenger side, and an operation unit corresponding thereto. That is, as a plurality of terminal devices, a power window motor 502, a door lock motor 503, and the like are connected to the communication unit 501, and a switch 504 that is an operation unit for driving the power window motor 502 and the like are communication units. Five
Connected to 01.

A slave station 550 is arranged on the door provided on the driver's side of the vehicle. The slave station 550 includes a communication unit 551 for communicating with the master station 10, a plurality of terminal devices provided on the door on the driver's seat side, and an operation unit corresponding thereto. That is, the power window motor 552 as a plurality of terminal devices, the door lock motor 553, and the like are included in the communication unit 551.
The switch 554, which is an operation unit for driving the power window motor 552, and the like are connected to the communication unit 551.

A child station 600 is arranged at a door provided on the left side of the rear seat of the vehicle. The slave station 600 is composed of a communication unit 601 for communicating with the master station 10, a plurality of terminal devices provided on the door, and an operation unit corresponding thereto. That is, a power window motor 602 and a door lock motor 603 are connected to the communication unit 601 as a plurality of terminal devices. Further, a switch 604, which is an operation unit for driving the power window motor 602, and the like are connected to the communication unit 601.

A child station 700 is arranged at a door provided on the right side of the rear seat of the vehicle. The slave station 700 includes a communication unit 701 for communicating with the master station 10, a plurality of terminal devices provided on the door, and an operation unit corresponding to these terminal devices. That is, a power window motor 702 as a plurality of terminal devices and a door lock motor 703 are each connected to the communication unit 701. A switch 704, which is an operation unit for driving the power window motor 702, is connected to the communication unit 701.

A child station 800 is arranged on the left rear side of the vehicle. This child station 800, a communication unit 801 for communicating with the parent station 10,
It is composed of a plurality of terminal devices arranged on the rear left side of the vehicle. That is, the table lamp 802, the turn signal lamp 803, and the license lamp 804 are connected to the communication unit 801.

A child station 900 is arranged on the rear right side of the vehicle. This slave station 900 has a communication unit 901 for communicating with the master station 10,
It is composed of a plurality of terminal devices arranged on the rear right side of the vehicle. That is, each of the tail lamp 902, the turn signal lamp 903, and the license lamp 904 is connected to the communication unit 901.

Further, the communication unit 11 of the master station 10 has a memory for temporarily storing information for transmission or information collected from each slave station. Similarly, each of the communication units 101, 201, 301, 401, 501, 551, 601, ..., 901 of the slave stations 100, 200, 300, 400, 500, 550, 600, ..., 900 has a memory for temporarily storing information for transmission or received information.

Next, the data format used in the basic operation of the vehicle communication device shown in FIG. 2 will be described with reference to FIG.

A unique address is set in advance for each of the plurality of slave stations 100, 200, 300, 400, 500, 550, 660, ..., 900, and the corresponding slave station is called by specifying this address. That is, each slave station monitors the address information transmitted from the master station 10, and when it matches with its own address, it judges that it has received a call and returns information DFb, which will be described later, to the master station 10. .

As a result, communication is performed between the master station 10 and the called slave station.

As shown in FIG. 3C, addresses i-2, i-1,
The data format DF is set for each slave station of i, i + 1, i + 2, .... Each of these data formats DF is formed from information DFa to be transmitted from the master station 10 to the corresponding slave station and information DFb to be transmitted from the slave station to the master station 10.

Next, the data format DF for the slave station having the address i will be described as a representative.

As shown in FIG. 3 (B), the information DFa is a 2-bit header signal HD indicating the beginning of data and address information ADS consisting of 6-bit address bits a0, a1, a2, ..., A5,
Drive information Rx consisting of 1-bit sleep bit SLP and 1-bit parity bit AP used to stop the slave station, and 16-bit data bits r0, r1, r2, ..., R15
And one parity bit Pr. The information DF6 is a 16-bit data bit t0, t1, t2, ...
, T15, 1-bit parity bit Pt, and 1-bit error bit CE. Further, a switching time S for switching the communication line is set between the information DFa and the information DFb, and communication is not performed in this switching time S.

Further, the unit bit forming various information is generated by the pulse width modulation method as shown in FIG. 3 (A), and the bit time Tb of each unit bit is set to, for example, 70 μsec. The data time Tf of each data format DF is set to 3.5 msec, for example.

Next, a basic operation, for example, an operation when the small lamp switch 102 of the slave station 100 is turned on will be described.

First, the master station 10 collects information related to the operation, the head signal HD, the address information ADS of the slave station 100, and the sleep bit.
Information DFa including SLP, parity bit AP, drive information Px, and parity bit Pr is transmitted to slave station 100. At this time, each data bit r0, r forming the drive information Rx
1, r2, ..., r15 are set to logical value "0",
The parity bit Pr is set to the logical value "1".

Next, the slave station 100 operates information Tx after the switching time S elapses.
And the parity bit Pt and the error bit CE
DFb is transmitted to the master station 10. At this time, when the information related to the operation of the small lamp switch 102 corresponds to the data bit t0, this data bit t0 is set to the logical value "0" and the other data bits t1, t2, t3, ... …, T15
Is set to a logical value "1". The parity bit Pt and the error bit CE are set to the logical value "0", respectively.

Next, when the master station 10 receives the information DFb from the slave station 100, it decodes the operation information Tx and determines that the small lamp switch 102 has been turned on because the data bit t0 has the logical value "0". To do. As a result, the master station 10 can handle the corresponding terminal device, that is, the small lamp 302 of the slave station 300 and the slave station 40.
0 small lamp 402, slave station 800 tail lamp 802,
License lamp 804, tail lamp 902 of slave station 900,
It is determined that the license lamp 904 should be turned on.

The master station 10 transmits, to the slave station 300, information DFa including drive information Rx indicating that the small lamp 302 should be turned on.

At this time, for example, when the data bit r0 is assigned corresponding to the small lamp 302, this data bit r0
Set r0 to logical value "0" and set other data bits
Set r1, r2, ..., r15 to the logical value "1".

When the slave station 300 receives the information DFa from the master station 10, it decodes the drive information Rx, and when it detects that only the data bit r0 has the logical value “0”, it determines that it is a lighting instruction for the small lamp 302. To do. This causes the slave station 300 to turn on the small lamp 302. Subsequently, when the switching time S elapses after the slave station 300 receives the information DFa from the master station 10, the information D
Fb is transmitted to the master station 10. At this time, since the slave station 300 does not have an operating unit, the data bits t0, t1, t2, ..., T15 are set to the logical value "1".

Similarly, the parent station 10 sets the small lamp 402 to the child station 400.
The small lamp 402 is turned on by transmitting the information DFa for turning on.

Similarly, the master station 10 has a tail lamp 802 for the slave station 800.
And the information DFa indicating that the license lamp 804 is turned on and the information DFa indicating that the tail lamp 902 and the license lamp 904 are turned on are transmitted to the slave station 900, whereby the tail lamp 802 and the license lamp 8 are transmitted.
04, the tail lamp 902 and the license lamp 904 are turned on.

Next, the operation at the time of starting the engine will be described with reference to FIG.

In step S1, the master station 10 monitors the ignition switch 13, and if the ignition switch 13 is turned on to start the engine, that is, if it is detected that the ignition key is in the start position, After the collection of information from the communicating slave station is completed, the communication with the slave station is temporarily stopped and step S3
Go to. In step S3, the position of the ignition key is read. Then, in step S5, the ignition switch 13
Is set to the logical value "1".

The process of reading the position of the ignition key described above is executed every predetermined time, for example, every 10 msec.

When the engine starts and the ignition key returns from the start position to the on position, the process proceeds from step S1 to S7, and it is determined whether the flag information FSTART has the logical value "1". As described above, since the flag information FSTART is set to the logical value "1" in step S5, the process proceeds from step S7 to S9.

In step S9, the previously collected information is collected again. For example, when the ON operation of the ignition switch is detected while communicating with the slave station of address (i-1) (hereinafter referred to as slave station (i-1)), the next slave station (i + 1) is called. The information collected from the previous slave station (i-1) is discarded and the same slave station (i-1) is called again to collect the information from this slave station (i-1). When the collection of information from the slave station (i-1) is completed, the step
Proceed to S11 to set the flag information FSTART to the logical value "0".

Succeedingly, in a step S13, the address of the slave station having the next calling order is set to (i + 1). Next, in step S15, the transmission data to be transmitted to the slave station (i + 1), that is, the drive information Rx and the like are read from the memory. In step S17, the transmission operation is started and the transmission data including the drive information Rx and the like is transmitted to the slave station (i.
+1).

Further, after the engine is started, the ignition key is in the ON position, and the flag information FSTART has the logical value "0". Therefore, steps S1 and S7 are performed to step S19.
Go to. In step S19, information including the operation information Tx transmitted from the slave station (i + 1), that is, received data is input via the communication IC. In step S21, the input received data is stored in the memory.

Similarly, the master station 10 sequentially polls the slave stations having the next calling order to collect information from each slave station.

As described above, when the engine is started, the power supply voltage may drop.In such a state, communication between the master station and the slave station is temporarily stopped, and the power supply voltage after the engine is started becomes normal. Since the communication with the slave station is started again in the restored state, it is possible to reliably prevent the malfunction due to the decrease in the power supply voltage.

In the example shown in FIG. 4, when the ignition key is at a position other than the start position, the process immediately proceeds from step S1 to step S7 to step S19 to collect information from the slave station. If a certain time has passed,
In other words, if it is configured to start collecting information from the slave station when the ignition key exists in a position other than the start position for a certain period of time or more, the time required for the power supply voltage that dropped when the engine started to return to a normal value Can be ensured, and the reliability of communication can be further improved.

As described above, according to the present invention, when the start position of the ignition switch is detected, the reception from the slave station 2 is temporarily stopped, while the start position of the ignition switch is changed. When it is no longer detected, the information related to the operation of the operating unit that has been temporarily stopped is discarded and the same slave station is called again to receive the information related to the operation of the operating unit. As the voltage drops, the information during communication cannot be read.When communication is stopped, the engine is started and the power supply voltage is restored, the information during communication is discarded and the same slave station is called again to receive information. By doing so, the reliability of the communication content can be improved.

[Brief description of drawings]

FIG. 1 is a diagram for responding to claims, FIG. 2 is a block diagram showing an overall configuration diagram of an embodiment according to the present invention, and FIG. 3 is an example of a data format set when a master station polls a slave station. FIG. 4 is a flow chart showing the operation of the embodiment shown in FIG. 1 ... Master station 2 ... Slave station 3 ... Multiple transmission line 4 ... Detecting means 5 ... Stop means 6 ... Communication control means

Claims (1)

[Claims] 1. A master station that sequentially calls slave stations, receives information relating to the operation of an operation unit, and transmits a drive signal for a terminal unit based on the information, and an operation of an operation unit that operates the terminal unit. A plurality of slave stations which transmit information related to the master station to the master station and receive a drive signal from the master station and drive the terminal unit based on the received drive signal; and the master station and the slave station electrically. In a vehicle communication device having a multiplex transmission line connected to, a detection unit for detecting whether or not an ignition switch position is present at a start position in the master station, and the start position is detected by the detection unit. When the start position is no longer detected by the detection means, the stop means for temporarily stopping the reception from the slave station,
Communication control means for discarding the information related to the operation of the operating unit that is temporarily stopped and calling the same slave station again to receive the information related to the operation of the operating unit. Vehicle communication device.