JPH1051475A - Vehicle data transmission system - Google Patents

Abstract

(57) [Problem] To provide a vehicle data transmission system adopting a token passing method which can easily manage a connection state of each node on a network to a bus. SOLUTION: Each of nodes 1a to 1c connected to a bus 3
, The delegation destination setting units 23a to 23c set transmission destination delegation nodes, and the transmission / reception units 21a to 23c transmit and receive data and transmit transmission right delegation messages to the set delegation destination nodes. 28a to 28c detect a reception response message sent from the delegation destination node that has received the delegation message, and the delegation destination setting unit determines that the reception response message is not detected from the delegation destination node within a predetermined time. , The connection information indicating the connection state of each delegation destination node to the bus is stored in the memory 25a based on the reception response message from each delegation destination node.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of nodes mounted on a vehicle connected to a bus, circulating a transmission right between the nodes in a predetermined order, and a node acquiring the transmission right being connected to the bus. The present invention relates to a vehicle data transmission system for transmitting data to a vehicle.

[0002]

2. Description of the Related Art In a vehicle such as an automobile, a plurality of electronic control nodes are connected to a common bus, and data is transmitted and received between the nodes. In this case, there is a token passing method in which the transmission right is circulated among the nodes in a predetermined order, and the node that has acquired the transmission right sends data to the bus.

[0003] As a technique of a vehicle data transmission system employing this kind of token passing system, for example, there is one disclosed in Japanese Patent Laid-Open No. 6-269048.

Japanese Patent Laid-Open No. Hei 6-269048 discloses a method of assigning the address of a delegation destination node to a value obtained by adding a value 1 to the address of a self-node, as shown in FIG. (Step S11)
1).

[0005] Then, it is determined whether or not there has been a reception response message of the transmission right delegation message from the delegation destination node (step S113). If there is a reception response message, the network is determined to be normal (step S11).
5), end the processing.

However, if there is no reception response message, the address of the next delegation destination node is set (step S117), and it is determined whether the set address is equal to the address of the own node (step S1).
19).

If the set address is different from the address of the own node, the process returns to step S111, where a transmission right transfer message is transmitted to the next transfer destination node based on the address of the next transmission destination node. To step S119.

When the set address becomes equal to the address of the own node, the network is determined to be abnormal.

According to such processing, it is possible to judge the system abnormality while performing the token transfer processing, so that other processing is not stopped, the transmission efficiency of the system is not reduced, and the network abnormality is performed. Can be detected.

[0010]

However, in the conventional token passing method, the reception response message received by the own node from the transfer destination node has not been effectively used as management information on the network.

For this reason, when a certain delegation destination node is not connected to the bus on the network, it is possible to determine which delegation destination node is not connected to the bus even if it can detect that the network is abnormal. I couldn't do that.

An object of the present invention is to provide a vehicle data transmission system capable of easily managing the connection state of each node on a network to a bus.

[0013]

The present invention employs the following means in order to solve the above-mentioned problems. A vehicle data transmission system according to claim 1, wherein a plurality of nodes are connected to a bus, a transmission right is circulated among the nodes in a predetermined order, and a node having acquired the transmission right sends data to the bus. , Each of the nodes transmits / receives data to / from a delegation destination setting unit that sets a delegation destination node of the transmission right, and transmits the transmission right to the delegation destination node of the transmission right set by the delegation destination setting unit. Transmitting and receiving means for transmitting the transfer right transfer message, detecting means for detecting a reception response message sent from the transmission right transfer destination node which has received the transmission right transfer message, and storage means for storing information. The delegation destination setting means, when a reception response message is not detected from the transmission right delegation destination node within a predetermined time, sets the next delegation destination node. Constant, and the subject matter that is stored in the storage means the connection information indicating the connection to the bus of the transfer destination node based on the received response message from the delegate node.

According to the present invention, the delegation destination setting means sets the transmission right delegation node, the transmission / reception means transmits and receives data, and the transmission right delegation destination node set by the delegation destination setting means. The transmission right delegation message is sent to the transmission right delegation message, and the detecting unit detects the reception response message transmitted from the transmission right delegation destination node that has received the transmission right delegation message.

The delegation destination setting means sets the next delegation destination node when a reception response message is not detected from the transmission right delegation destination node within a predetermined time, and sets the next delegation destination node. Based on the reception response message, the storage unit stores connection information indicating the connection state of each delegation destination node to the bus.

Therefore, the connection state of each node on the network to the bus can be easily managed.

In the invention according to claim 2, the delegation destination setting means determines that the delegation destination node is not connected to the bus when the reception response message is not detected from the transmission right delegation destination node. The gist is to store the address of the destination node in the storage means.

According to this invention, the delegation destination setting means determines that the delegation destination node is not connected to the bus when the reception response message is not detected from the transmission right delegation destination node. Is stored in the storage means, so that nodes not connected to the bus can be easily identified.

In the invention according to claim 3, the delegation destination setting means sets the next delegation destination node by incrementing an address of the delegation destination node.

According to the present invention, the delegation destination setting means sequentially sets the next delegation destination node by incrementing the address of the delegation destination node, so that which delegation destination node is not connected to the bus is determined. Recognize.

According to the fourth aspect of the present invention, the delegation destination setting means sets the transmission right to a delegation destination node having a predetermined transmission right when the set delegation destination node address becomes the address of the own node. And that the address of the own node is stored in the storage means.

According to the present invention, the delegation destination setting means determines that when the set delegation destination node address becomes the address of its own node, the transmission right goes around the delegation destination node having the predetermined transmission right. Since the address of the own node is stored in the storage means, it can be understood that nodes other than the own node are not connected to the bus.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle data transmission system according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration diagram of an embodiment of a vehicle data transmission system according to the present invention. In the vehicle transmission system shown in FIG. 1, an engine control node 1a, a mission control node 1b, and a brake control node 1c are connected to a bus 3, and necessary data is transmitted and received between the nodes by a token passing method.

That is, the transmission right is circulated among the nodes 1a to 1c in a predetermined order, and the node which has acquired the transmission right sends the data to the bus 3.

The engine control node 1a controls the operation of the engine according to the driver's operation of the accelerator pedal or the like. The mission control node 1b controls the automatic transmission according to the driving state of the vehicle. Brake control node 1c
Performs brake control by detecting the locked state of the wheels.

The engine control node 1a includes a CPU (central processing unit) 11a, a transmitting / receiving unit 21a, a transfer destination setting unit 23
a, a memory 25a, a detection unit 28a, and a counter 30a.

The engine control node 1a is connected to a sensor 31a provided in each part of the vehicle for detecting a running state and an actuator 41a.

Although only one sensor 31a is shown in FIG. 1, it is assumed that a plurality of sensors 31a are actually provided. The CPU 11a drives the actuator 41a based on a detection signal from the sensor 31a.

The mission control node 1b and the brake control node 1c have the same configuration as that of the engine control node 1a. That is, the mission control node 1b
Is a CPU 11b, a transmitting / receiving unit 21b, a transfer destination setting unit 23
b, a memory 25b, a detection unit 28b, and a counter 30b.

The brake control node 1c has a CPU 11
c, transmission / reception unit 21c, delegation destination setting unit 23c, memory 25
c, a detection unit 28c, and a counter 30c.

The delegation destination setting units 23a to 23c set the delegation destination node of the transmission right by the address of the delegation destination node, and set the next delegation destination node by incrementing the address of the delegation destination node. .

Each of the delegation destination setting units 23a to 23c has an address management table (not shown).
It manages each address of its own node and the next node.

The transmission / reception units 21a to 21c transmit and receive data and transmit a transmission right transfer message to the transmission right transfer destination node set by the transfer destination setting units 23a to 23c.

The detecting units 28a to 28c detect the reception response message sent from the transmission right transfer destination node which has received the transmission right transfer message. Memory 2
5a to 25c store various information.

The counters 30a to 30c count the time from the time when the delegation destination setting units 23a to 23c set the transmission right delegation destination node to a predetermined timeout period, and send the timeout signal when the timeout period elapses. Output to the setting units 23a to 23c.

The delegation destination setting units 23a to 23c set the next delegation destination node when a reception response message is not detected from the transmission right delegation destination node within the timeout time counted by the counters 30a to 30c. And
The connection information indicating the connection state of each delegation destination node to the bus 3 is stored in the memories 25a to 25c based on the reception response message from each delegation destination node.

When no reception response message is detected from the transmission right delegation node, the delegation destination setting units 23a to 23c determine that the delegation destination node is not connected to the bus 3 and determine whether the delegation destination node is not connected to the bus 3. Address 25
a to 25c.

When the address of the set delegation destination node becomes the address of the own node, the delegation destination setting units 23a to 23c determine that the transmission right has gone through the delegation destination node of the predetermined transmission right, and Node address is stored in memory 25
a to 25c.

FIG. 2 shows the format of a data frame according to the embodiment. In FIG. 2, the data frame includes an SOM indicating the start of a message, a transfer destination address indicating an address of a transfer right transfer destination node, a transmission source address, data, an error detection character string CRC, reception acknowledgment information, and an end of the message. EOM shown.

The transfer destination address may be set to a value of 0 to 2 corresponding to each control node.

The data includes a data byte length, a data identifier, and information to be transmitted. The reception acknowledgment information includes reception acknowledgment information from a node that has successfully received data and reception acknowledgment information from a node that has normally received a transmission right.

Next, the operation of the thus configured vehicle data transmission system of the embodiment will be described with reference to the flowchart shown in FIG.

Here, for example, the engine control node 1
a, mission control node 1b, brake control node 1
The case where the transmission right circulates in the order of c and the mission control node 1b is not connected to the bus 3 will be described.

First, the transmission / reception unit 21a of the engine control node 1a receives the transfer destination address "1a" and the transmission source address "1e" from the brake control node 1c, and obtains the transmission right.

Then, the transfer destination setting unit 23a in the engine control node 1a sets the transfer destination address to the next transfer destination address "1b (address of the mission control node)".

Transmission / reception section 21a of engine control node 1a
Sends a transmission right transfer message to the mission control node 1b, which is the transfer destination node (step S11).

Next, the counter 30a is set in the transfer destination setting section 2
The time is counted from the time when 3a sets the transmission right transfer destination node to a predetermined timeout time (step S13).

When the count time reaches the timeout time, the counter 30a outputs a timeout signal to the transfer destination setting unit 23a.

Next, the detection unit 2 of the engine control node 1a
8a, when the mission control node 1b, which is the transmission right delegation node that has received the transmission right delegation message, sends a reception response message (reception acknowledgment information shown in FIG. 2) to the engine control node 1a. The reception response message is detected via the transmission / reception unit 21a.

The transfer destination setting unit 23a determines whether a reception response message has been received within the timeout period based on the timeout signal from the counter 30a and the detection signal from the detection unit 28a (step S1).
5).

Here, the timeout time is, for example,
It is 140 ms. Normal, i.e., when the control node 1a~1c are connected to the bus 3, as shown in FIG. 4, an engine control node 1a is at the time t _1,
Send the transfer message _P1a to the mission control node 1b.

In FIG. 4, the transmission of the transfer message P _1a from the engine control node 1a to the mission control node 1b is indicated by 1a → 1b.

[0054] Then, at time t ₂ has elapsed from the time t ₁ by 100 ms, the transmission control node 1b is sending a delegation message P _1b of transmission right to the brake control node 1c. In FIG. 4, transmission of the transfer message P _1b from the mission control node 1b to the brake control node 1c is indicated by 1b → 1c.

That is, the mission control node 1b sends a reception response message to the engine control node 1a within the timeout period.

[0056] Further, at time t ₃ when has elapsed 100ms from time t _2, the brake control node 1c has sent a delegation message P _1c of transmission right to the engine control node 1a. In FIG. 4, the transmission of the transfer message P _1c from the brake control node 1c to the engine control node 1a is indicated by 1c → 1a.

That is, the brake control node 1c sends a reception response message to the mission control node 1b within the timeout period.

Meanwhile, abnormal, i.e., when the admission control node 1b to the bus 3 is not connected, as shown in FIG. 5, the timeout time (time t ₁ time t ₄ from
The engine control node 1a does not receive the reception response message from the mission control node 1b, which is the node to which the transmission right has been delegated, within the time period up to).

The mission control node 1b does not send a transmission right transfer message to the brake control node 1c. In FIG. 5, the transmission right transfer message is not transmitted from the mission control node 1b to the brake control node 1c at the time t ₂ by a pulse indicated by a dotted line.

For this reason, the delegation destination setting unit 23a of the engine control node 1a sets the address of the brake control node 1c which is the next delegation destination node of the mission control node 1b at the time of timeout (step S17).

Further, the transfer destination setting unit 23a determines whether the set address is its own address (step S19).

If the set address is not its own address, the transfer destination setting unit 23a stores the address value “1b” of the mission control node 1b, which is an unconnected node, in the memory 25a (step S21).

[0063] Then, the process returns to step S11, at time t ₄ is a time-out, the engine control node 1a transmits the delegation message P _2a of the transmission right to the brake control node 1c. In Figure 5, the delivery of the delegation message P _2a from engine control node 1a to the brake control node 1c, are indicated by 1a → 1c.

Next, the brake control node 1c operates at time t.
At time t ₅ that has elapsed 100ms _4, and sends the delegation message P ^1c of transmission right to the engine control node 1a. In FIG. 5, the transmission of the transfer message P _1c from the brake control node 1c to the engine control node 1a is indicated by 1c → 1a.

That is, the brake control node 1c sends a reception response message to the mission control node 1b within the timeout period.

On the other hand, if the set address is the own address in step 19, that is, if no control node other than the own node is connected to the bus 3, the transfer destination setting unit 23a sets the own address to 1a "is stored in the memory 25a (step S23). Then, the communication device is reset (step S25).

If the own node has received the reception response message from the delegation destination node in step 15, the process ends.

As described above, in the vehicle data transmission system adopting the token passing method, the transmission right transfer message is transmitted to the transfer destination node, and the reception response message or the transmission right transfer from the transfer destination node is transmitted within the timeout period. When the message is not transmitted, it is assumed that the transfer destination node is not connected to the bus 3 and that a control node other than the transfer destination node is connected to the bus 3.

Since the connection information of these control nodes is stored in the memory 23a, the connection state of each control node on the network can be easily managed.

By reading the connection information stored in the memory 23a, for example, the mission control node 1b is not connected to the bus 3 and the engine control node 1a and the brake control node 1c are connected to the bus 3. Can be easily understood.

In the embodiment, the example in which the delegation destination setting unit 23a stores the information of the node not connected to the bus 3 in the memory 25a in the engine control node 1a has been described. The delegation destination setting unit 23c may store information on nodes not connected to the bus 3 in the memory 25c.

In the embodiment, the number of nodes is three, but the number of nodes is not limited to three.
There may be four or more.

For example, an output torque control node, a suspension control node, and the like may be further connected to the bus 3 to form a vehicle data transmission system.

The output torque control node detects the slip state of the drive wheels of the vehicle and controls the output torque of the engine. The suspension control node controls the suspension according to the driving state of the vehicle.

Further, in the embodiment, the mission control node 1b is not connected to the bus 3, but, for example, the engine control node 1a or the brake control node 1c may not be connected to the bus 3.

In the embodiment, the timeout time is set to 140 ms. However, the timeout time is not limited to this time value, but may be another time value.

[0077]

According to the present invention, the delegation destination setting means sets the transmission right delegation node, the transmission / reception means transmits and receives data, and delegates the transmission right set by the delegation destination setting means. The transmission right transfer message is sent to the destination node, and the detecting means detects the reception response message sent from the transmission right transfer destination node that has received the transmission right transfer message.

When the reception response message is not detected from the transmission right delegation destination node within a predetermined time, the delegation destination setting means sets the next delegation destination node. Based on the reception response message, the storage unit stores connection information indicating the connection state of each delegation destination node to the bus.

Therefore, the connection state of each node on the network to the bus can be easily managed.

The transfer destination setting means determines that the transfer destination node is not connected to the bus when the reception response message is not detected from the transfer right transfer destination node, and stores the address of the unconnected transfer destination node in the storage means. Since the information is stored, a node not connected to the bus can be easily identified.

Further, the delegation destination setting means sets the next delegation destination node in order by incrementing the address of the delegation destination node, so that it is possible to know which delegation destination node is not connected to the bus.

Further, the delegation destination setting means determines that when the set delegation destination node address becomes its own node address, the transmission right goes around the delegation destination node having the predetermined transmission right, and Is stored in the storage means, it can be understood that nodes other than the own node are not connected to the bus.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a vehicle data transmission system of the present invention.

FIG. 2 is a diagram illustrating a format of a data frame according to the embodiment;

FIG. 3 is a flowchart illustrating the operation of the vehicle data transmission system of the present invention.

FIG. 4 is a diagram showing transmission of a transmission right transfer message of each control node when each control node is connected to a bus.

FIG. 5 is a diagram illustrating transmission of a transmission right transfer message of each control node when the mission control node is not connected to the bus.

FIG. 6 is a flowchart illustrating the operation of a conventional vehicle data transmission system.

[Explanation of symbols]

 1a Engine control node 1b Mission control node 1c Brake control node 11a to 11c CPU 21a to 21c Transmitting and receiving unit 23a to 23c Delegation destination setting unit 25a to 25c Memory 28a to 28c Detecting unit 30a to 30c Counter 31a to 31c Sensor 41a to 41c Actuator

Claims (4)

[Claims] 1. A vehicle data transmission system in which a plurality of nodes are connected to a bus, a transmission right is circulated among the nodes in a predetermined order, and a node having acquired the transmission right sends data to the bus. Each of the nodes transmits and receives data to and from a delegation destination setting unit that sets the delegation destination node of the transmission right, and transmits a transmission right delegation message to the transmission right delegation destination node set by the delegation destination setting unit. Transmission / reception means for transmitting the transmission right delegation message, detection means for detecting a reception response message sent from the transmission right delegation destination node which has received the transmission right delegation message, and storage means for storing information, The destination setting means sets a next delegation node when a reception response message is not detected from the transmission right delegation node within a predetermined time. Vehicle data transmission system, characterized in that to store the connection information indicating a connection state to the bus for each transfer destination node based on the received response message from the transfer destination node in the storage means. 2. The method according to claim 1, wherein the delegation destination setting unit determines that the delegation destination node is not connected to the bus when the reception response message is not detected from the transmission right delegation destination node. The vehicle data transmission system according to claim 1, wherein the vehicle data is stored in the storage unit. 3. The vehicle data transmission system according to claim 1, wherein the delegation destination setting unit sets the next delegation destination node by incrementing an address of the delegation destination node. . 4. The delegation destination setting means, when the set delegation destination node address becomes the address of its own node, determines that the transmission right has circled the delegation destination node having a predetermined transmission right, and 4. The vehicle data transmission system according to claim 3, wherein an address of the node is stored in said storage means.