KR101567973B1 - Can communication apparatus and method - Google Patents

Abstract

The present invention relates to an apparatus for CAN communications. The apparatus for CAN communications between multiple nodes, connected to each other through one communications bus, includes: a voltage sensing unit which senses use voltage between at least one pair of nodes while CAN communications between the nodes is performed through the communications bus; a control unit which sets voltage, different from the use voltage between the nodes which is sensed by the voltage sensing unit, as use voltage; a voltage generation unit which generates the use voltage set by the control unit; and a transceiver which transmits and receives data based on the use voltage generated by the voltage generation unit.

Description

CAN COMMUNICATION APPARATUS AND METHOD "

The present invention relates to a can communication apparatus and method, and more particularly, to a can communication apparatus and method capable of simultaneously transmitting and receiving data through a plurality of nodes by setting different usable voltage levels for a plurality of nodes connected to each other via a single communication bus Apparatus and method.

Recently, due to the development of electronic control technology, various devices which are operated by a mechanical method in a vehicle have been driven by an electric method because of convenience of the driver and safety of operation.

For example, in a manual transmission that changes the running speed and torque of a vehicle in accordance with the operation of the shift lever of a driver, the transmission of the vehicle is controlled by a transmission control unit (TCU ) To change the running speed and torque of the vehicle.

Further, the braking device of the vehicle is not limited to the braking of the vehicle only by the operation of the brake pedal of the driver. In addition to the operation of the brake pedal of the driver through the anti-lock brake system (ABS) A technique for improving the stability of vehicle operation by braking the vehicle has been developed.

In recent years, a technology has been developed to drive a vehicle with super lean burn by means of a GDI (Gasoline Direct Injector) engine for the purpose of high output, high fuel efficiency and exhaust gas reduction of the engine. In such a GDI engine, The opening ratio of the throttle valve is controlled by an electronic throttle controller (ETC) in order to suppress the sudden fluctuation of the engine torque when the air-fuel ratio is changed, .

Electronic devices such as the above-described shift control device, anti-skid device, and electronic throttle controller receive various kinds of information of a vehicle necessary for operating each system through in-vehicle communication.

In particular, there is a CAN (Controller Area Network) communication with the most familiar communication as in-vehicle communication.

Can communication is a vehicle network system developed to perform data communication between various electronic devices in a vehicle and is a communication network system which is excellent in price and performance and is stable and reliable in a vehicle in which adverse influences such as shock, vibration, noise, Environment.

Can communication system generally includes a communication bus line made up of two wires (CAN-High, CAN-Low) and a terminating resistor connected to both ends of the communication bus line to constitute a communication bus line as a closed circuit, So that the electronic devices connected to the communication bus line can transmit and receive data.

As a prior art related to the present invention, Korean Patent Laid-Open Publication No. 2012-0119890 (published on October 31, 2012, entitled "Invention of Car Can Communication Device") is available.

Such can communication has a variety of advantages as described above. However, when data is to be simultaneously transmitted from a plurality of nodes, a message having a high priority is transmitted first and a message having a low priority is delayed according to a priority .

In other words, can communication can be transmitted only from one node at a time because a plurality of nodes are connected in parallel to one communication bus, and in order to proceed communication at another node, wait until the current communication is completed .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages, and it is an object of the present invention to provide a CAN communication device and a CAN communication device capable of simultaneously transmitting and receiving data through a plurality of nodes by setting different usable voltage levels for a plurality of nodes connected to each other via one communication bus The purpose of the method is to provide.

A can communication device according to an aspect of the present invention is a communication device that can communicate with a plurality of nodes connected to each other via a communication bus, A voltage sensing unit for sensing a voltage between nodes; A control unit for setting a voltage to be used at a voltage different from the voltage between the pair of nodes sensed through the voltage sensing unit; A voltage generator for generating a use voltage set through the controller; And a transceiver for transmitting and receiving data based on a voltage generated by the voltage generator.

In the present invention, the controller may set a voltage to be used such that the voltage between the pair of nodes sensed through the voltage sensing unit is greater than a predetermined reference value.

In the present invention, when the can communication between two or more pairs of nodes is in progress via the communication bus, the control unit sets a voltage that is different from the sum or difference of the voltages used between the two or more pairs of nodes.

In the present invention, the transceiver transmits / receives data based on the generated voltage before completion of communication between the pair of nodes or more.

In the present invention, the control unit may set a used voltage to a predetermined reference voltage when a voltage between one or more nodes is not detected through the voltage sensing unit.

A can communication method according to an aspect of the present invention is a can communication method between a plurality of nodes connected to each other through a communication bus, the can communication method comprising the steps of: Sensing a voltage between one or more of the nodes; The control unit setting the use voltage to a voltage different from the at least one pair of inter-node usage voltages; Generating a voltage for use by the voltage generator through the controller; And a transceiver transmitting and receiving data based on a use voltage generated through the voltage generator.

In the step of setting the voltage for use according to the present invention, the controller may set the voltage to be used so that the voltage between the one or more nodes is different from the voltage between the nodes by a preset reference value or more.

In the present invention, it is preferable that the step of detecting the voltage between one or more nodes further includes a step of determining whether there are two or more pairs of nodes in which the can communication is in progress, And when the can communication is in progress, a voltage different from a sum or difference of the voltages used between the two or more nodes is set as a working voltage.

The transceiver transmits and receives data based on the generated voltage before completion of communication between the pair of nodes or more, in the step of transmitting and receiving data based on the generated use voltage of the present invention.

In the step of setting the use voltage of the present invention, the control unit may set the use voltage to a predetermined reference voltage when the voltage between one or more nodes is not detected through the voltage sensing unit.

According to the present invention, data transmission and reception can be performed simultaneously through a plurality of nodes by assigning different usable voltage levels to a plurality of nodes connected to each other through one communication bus.

Further, since the present invention can simultaneously transmit and receive a plurality of data, it is possible to increase the communication speed and bandwidth in proportion to data transmitted and received at the same time.

1 is a functional block diagram of a can communication device according to an embodiment of the present invention.
2 is a diagram comparing signals on a communication bus of a conventional CAN communication device with signals on a communication bus of a CAN communication device according to an embodiment of the present invention.
FIG. 3 is a flowchart illustrating an implementation procedure of a can communication method according to an embodiment of the present invention.

Hereinafter, a can communication apparatus and method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, and these may vary depending on the intention or custom of the driver, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

1 is a functional block diagram of a can communication device according to an embodiment of the present invention.

1, the CAN communication device includes a voltage sensing unit 10, a control unit 20, a voltage generating unit 30, and a transceiver 40.

In this embodiment, the can communication device may be an engine control unit (ECU), a transmission control unit (TCU), an anti-lock brake system (ABS) And an electronic throttle control system (ETCS), which are capable of transmitting and receiving various data in the vehicle via can communication.

The voltage sensing unit 10 senses the voltage used between the nodes that are performing can communication when the can communication is in progress.

Specifically, the voltage sensing unit 10 senses the voltage between the nodes that are performing CAN communication through the voltage difference between the CAN (Controller Area Network) -High wiring of the communication bus and the CAN-Low wiring.

That is, according to CAN communication protocol, CAN communication transmits / receives data through voltage difference between CAN-High wiring and CAN-Low wiring. Therefore, if the voltage across CAN-High wiring and CAN- Can be judged as being in progress.

When the can communication is in progress, the voltage sensing unit 10 senses the used voltage to determine which voltage the two nodes, which are in actual can communication, are exchanging data with.

However, the present embodiment is not limited to this, and it is possible to confirm whether or not the can communication is proceeded through various other methods.

For example, since the message used for the can communication includes a start field for informing other nodes that the message transmission is started, the voltage sensing unit 10 checks the start field of the message transmitted and received via the communication bus, It is also possible to confirm the progress.

The control unit 20 sets a voltage to be used for data transmission / reception with a voltage different from a voltage between one or more nodes sensed through the voltage sensing unit 10.

Conventionally, only a pair of nodes among a plurality of nodes connected through a communication bus can proceed communication, and another pair of nodes have to wait until the current communication is completed to start communication.

At this time, in the CAN communication, based on the point that data is transmitted / received through a voltage difference between the CAN-High wiring and the CAN-Low wiring, in the present embodiment, So that data can be transmitted and received through a plurality of node pairs at the same time.

Specifically, the control unit 20 sets the voltage to be used so that the voltage between one or more nodes sensed through the voltage sensing unit 10 is greater than a preset reference value.

In other words, noise may be mixed in the voltage used between the nodes sensed through the communication bus. Therefore, the control unit 20 determines a new use voltage that is different from the use voltage being used by the currently- By this setting, it is prevented that the data at each use voltage is mixed with each other due to the noise.

At this time, the reference value means a variation amount of the operating voltage to such a degree that it is changed due to the noise normally occurring on the communication bus, and it can be set based on the size of the noise normally occurring on the communication bus or the performance of the communication bus .

In addition, when the can communication between two or more pairs of nodes is in progress, the control unit 20 sets a voltage that is different from the sum or difference of the voltages between two or more pairs of nodes to the using voltage.

That is, when only a pair of nodes is in communication, each data can be normally transmitted to each node only by transmitting and receiving data using a voltage different from that of the node.

However, in a situation where two pairs of nodes are in can communication, when the sum of the voltages used between two pairs of nodes is set to the using voltage, the transmitting and receiving is performed through the transceiver 40, which will be described later, May not be distinguished from each other.

Similarly, when two pairs of nodes are in communication with each other, when the voltage difference between the two pairs of nodes is set to the working voltage, the signals of one pair of the two pairs of nodes and the signal transmitted / received through the transceiver 40 overlap The signal of the other pair of nodes may not be distinguished.

Therefore, in this embodiment, when the can communication between two or more pairs of nodes is in progress, the control unit 20 sets the voltage to be used as a voltage different from the sum or difference of the voltages between two or more pairs of nodes, So that signals can be distinguished from each other even if the signals overlap.

On the other hand, if no voltage is detected between one or more of the nodes through the voltage sensing unit 10, that is, if the current can communication is not proceeding, the control unit 20 sets the used voltage to a preset reference voltage.

That is, when the current can communication is not in progress, the control unit 20 sets the used voltage as the reference voltage since there is no used voltage to be avoided.

At this time, the reference voltage may be set to a voltage to be used when transmitting / receiving data in a general can communication device.

The voltage generating unit 30 generates a use voltage set through the control unit 20. [

That is, the voltage generating unit 30 generates a voltage difference between the CAN-High wiring and the CAN-Low wiring necessary for can communication. In this embodiment, the control unit 20 controls the voltage generating unit 30 to transmit and receive data through a plurality of node pairs, Lt; / RTI >

The transceiver 40 transmits and receives data based on the use voltage generated through the voltage generator 30. [

Particularly, in the present embodiment, the transceiver 40 transmits and receives data based on the voltage generated by the voltage generating unit 30 before the can communication between one or more nodes is terminated.

That is, in the present embodiment, even if another pair of nodes is performing can communication through one communication bus, data is transmitted and received based on the use voltage different from the use voltage of the corresponding communication before the can communication is ended, It is possible to transmit and receive data between the nodes of the network.

Hereinafter, technical features of the can communication device according to the present embodiment will be described in more detail.

2 is a diagram comparing signals on a communication bus of a conventional CAN communication device with signals on a communication bus of a CAN communication device according to an embodiment of the present invention.

Referring to FIG. 2, (A) of FIG. 2 shows a voltage difference between a signal sensed in CAN-High wiring and CAN-Low wiring and a voltage difference in both wiring due to communication of a pair of nodes on a communication bus of a conventional CAN communication device 2 (B) shows the difference between the signals sensed in the CAN-High wiring and CAN-Low wiring and the voltage difference in both wiring due to the communication of the two pairs of nodes on the communication bus of the CAN communication apparatus according to this embodiment .

Specifically, it is assumed that the voltage used by a pair of nodes in the conventional CAN communication apparatus is 3 V, and that the voltages used between the two pairs of nodes a and b in the CAN communication apparatus according to the present embodiment are 2 V and 3 V, respectively.

As shown in Fig. 2, in this embodiment, can communication between two or more pairs of nodes can be performed at the same time by generating a plurality of used voltages.

2 (A) and 2 (B) are shown in Table 1 and Table 2 below.

0V 3V Signal discrimination Recessive Dominant Communication Bus Status Recessive Dominant

0V 2V 3V 5V Signal discrimination (a) Recessive Recessive Dominant Dominant Signal discrimination (b) Recessive Dominant Recessive Dominant Communication Bus Status Recessive Dominant Dominant Dominant

Table 1 shows the result of discrimination of node signal and communication bus state in each section of Fig. 2 (A), Table 2 shows the result of discrimination of node signal and communication bus state in each section of Fig. 2 (B) Results are shown.

As shown in Table 1, when there is no CAN communication, Vdiff is 0 V because there is no voltage difference between CAN-High wiring and CAN-Low wiring, and the communication bus becomes a Recessive state indicating that CAN communication is not in progress.

In case CAN communication is in progress between specific nodes, there is a voltage difference between CAN-High wiring and CAN-Low wiring. Vdiff is 3V because the use voltage is 3V as described above. The dominant state is represented.

On the other hand, when two pairs of nodes can communicate simultaneously, as shown in Table 2, when CAN communication does not proceed, Vdiff is shown as 0 V because there is no voltage difference between CAN-High wiring and CAN- Recessive state.

In addition, since two pairs of nodes can communicate, the voltage difference between CAN-High wiring and CAN-Low wiring can be expressed in three forms. Specifically, Vdiff is 2V and 3V for each use voltage, and 5V And the communication bus becomes dominant.

As described above, when only one pair of nodes communicate with each other on the communication bus of the conventional CAN communication device, there are only two periods of Vdiff section, 0 V and 3 V. According to this embodiment, the Vdiff section is 0 V, And 5V, respectively.

At this time, since the voltage between two pairs of nodes is assumed to be 2V and 3V, the voltage difference between CAN-High wiring and CAN-Low wiring is 5V in the overlapping signal of each node.

Therefore, in the present embodiment, when setting the voltage to be used, the control unit 20 sets the use voltage at a voltage different from the sum or difference of the voltages used between two or more nodes to determine whether the signal in the corresponding interval is a superimposed signal, So that the signal can be clearly distinguished.

As described above, in this embodiment, different use voltages are assigned to the respective node pairs for conducting can communication, so that data transmission / reception in a plurality of node pairs is possible at the same time.

Particularly, in one communication bus of the can communication device according to the present embodiment, data is transmitted and received to and from a plurality of nodes at the same time. Therefore, when data transmission / reception at each node is called a thread, Threads can be said to be possible.

In the present embodiment, the subject performing can communication is represented by a node. However, in actual communication of the vehicle can, each node may communicate with the other communication device such as an engine control device, a shift control device, a slip prevention device, Electronic device.

That is, if all the electronic apparatuses capable of performing can communication communicate according to the above-described technique, if the can communication apparatus is in the can communication state, data is transmitted and received at a use voltage different from that of the can communication apparatus, Can communication can proceed without need.

FIG. 3 is a flowchart illustrating an implementation procedure of a can communication method according to an embodiment of the present invention.

Referring to FIG. 3, a can communication method according to an exemplary embodiment of the present invention will be described. First, when communication between one or more pairs of nodes is in progress via a communication bus (S10) The operating voltage between the at least one pair of nodes is detected (S20).

Specifically, the voltage sensing unit 10 senses the voltage between the nodes that are performing CAN communication through the voltage difference between the CAN (Controller Area Network) -High wiring of the communication bus and the CAN-Low wiring.

Then, the control unit 20 sets the using voltage to a voltage different from the operating voltage between the at least one pair sensed through the voltage sensing unit 10 (S30).

That is, in the CAN communication, based on the point that data is transmitted / received through the voltage difference between the CAN-High wiring and the CAN-Low wiring, in the present embodiment, even if CAN communication is in progress between specific nodes, Data is transmitted and received at a voltage different from that of the used voltage so that data can be transmitted and received through a plurality of node pairs at the same time.

To this end, the control unit 20 sets the usable voltage so that the usable voltage between one or more nodes sensed through the voltage sensing unit 10 is more than a predetermined reference value.

That is, noise may be mixed in the voltage used between the nodes sensed through the communication bus. Therefore, the control unit 20 sets a new usable voltage which is different from the voltage being used by the node currently in communication with the can, Thereby preventing mixing of data at a specific operating voltage due to noise.

When the voltage between two or more pairs of nodes is detected through the voltage sensing unit 10 in the above-described step S20, the controller 20 controls the voltage difference between the voltage and the voltage .

That is, when only a pair of nodes is in communication, each data can be normally transmitted to each node only by transmitting and receiving data using a voltage different from that of the node.

However, in a situation where two pairs of nodes are in can communication, when the sum of the voltages used between two pairs of nodes is set to the using voltage, the transmitting and receiving is performed through the transceiver 40, which will be described later, May not be distinguished from each other.

Similarly, when two pairs of nodes are in communication with each other, when the voltage difference between the two pairs of nodes is set to the working voltage, the signals of one pair of the two pairs of nodes and the signal transmitted / received through the transceiver 40 overlap The signal of the other pair of nodes may not be distinguished.

Therefore, in this embodiment, when the can communication between two or more pairs of nodes is in progress, the control unit 20 sets the voltage to be used as a voltage different from the sum or difference of the voltages between two or more pairs of nodes, So that signals can be distinguished from each other even if the signals overlap.

On the other hand, when the CAN communication is not in progress through the communication bus, the control unit 20 sets the used voltage to a preset reference voltage (S32).

That is, when the current can communication is not in progress, the control unit 20 sets the used voltage as the reference voltage since there is no used voltage to be avoided.

Next, the voltage generator 30 generates a use voltage set through the controller 20 (S40), and the transceiver 40 transmits and receives data based on the use voltage generated through the voltage generator 30 S50), the can communication can be performed simultaneously with the node pair which is already in the can communication.

According to the present embodiment, data transmission / reception can be simultaneously performed through a plurality of nodes by assigning different usable voltage levels to a plurality of nodes connected to each other via one communication bus.

In addition, since the present embodiment can transmit and receive a plurality of data at the same time, it is possible to increase the communication speed and bandwidth in proportion to data transmitted and received at the same time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Accordingly, the true scope of the present invention should be determined by the following claims.

10:
20:
30:
40: Transceiver

Claims (10)

A CAN communication apparatus for a plurality of nodes connected to each other via a communication bus, the apparatus comprising: a voltage sensing unit for sensing a voltage between one or more nodes when CAN communication is in progress via the communication bus;
A control unit for setting a voltage to be used at a voltage different from the voltage between the pair of nodes sensed through the voltage sensing unit;
A voltage generator for generating a use voltage set through the controller; And
A transceiver for transmitting and receiving data based on a voltage used by the voltage generator,
Lt; / RTI >
The method according to claim 1,
Wherein the control unit sets the use voltage so that the use voltage of the one or more pairs sensed through the voltage sensing unit is different from a predetermined reference value.
The method according to claim 1,
Wherein the control unit sets a voltage that is different from a sum or difference of the voltages used between the two or more pairs when the can communication between two or more pairs of nodes is in progress via the communication bus.
The method according to claim 1,
Wherein the transceiver transmits and receives data based on the generated voltage before completion of can communication between the pair of nodes or more.
The method according to claim 1,
Wherein the control unit sets the used voltage to a preset reference voltage when the voltage between one or more of the nodes is not detected through the voltage sensing unit.
A method of communication between a plurality of nodes connected to each other through a communication bus, the method comprising the steps of: detecting a voltage between a pair of nodes when the voltage sensing unit is in communication with one or more nodes via the communication bus; ;
The control unit setting the use voltage to a voltage different from the at least one pair of inter-node usage voltages;
Generating a voltage for use by the voltage generator through the controller; And
A transceiver transmits and receives data based on a use voltage generated through the voltage generator
Lt; / RTI >
The method according to claim 6,
Wherein the control unit sets the use voltage so that the use voltage of the one or more pairs is greater than a preset reference value.
The method according to claim 6,
Wherein the step of sensing the voltage between one or more nodes further comprises determining whether two or more nodes in the can communication are more than two, And when it is in progress, sets a voltage that is different from the sum or difference of the voltages used between the two or more pairs of nodes to the using voltage.
The method according to claim 6,
Wherein the transceiver transmits and receives data based on the generated voltage before completion of can communication between the pair of nodes or more in the step of transmitting and receiving data based on the generated use voltage.
The method according to claim 6,
Wherein in the step of setting the use voltage, the control unit sets the use voltage to a predetermined reference voltage when the voltage between one or more nodes is not detected through the voltage sensing unit.

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