KR20190081958A - System and method for controlling load factor of internal communication bus of car, and a recording medium having computer readable program for executing the method - Google Patents

Abstract

Disclosed are a system and method for controlling a load rate of an in-vehicle communication bus, and a recording medium having a computer readable program for executing the same. The system for controlling a load rate of an in-vehicle communication bus comprises a load rate measurement unit, a warning message transmission unit, and a transmission cycle control unit. The load rate measurement unit is configured to measure a load rate of the in-vehicle CAN bus. When an overload occurs, in which a load rate exceeds a predetermined overload threshold value, the message transmission unit is configured to transmit a warning message to a bus having a load rate exceeding the overload threshold value. The transmission cycle control unit is configured to control a transmission cycle of a transmission message which a controller having received the warning message transmits. Accordingly, when the CAN bus is overloaded, a warning message is transmitted to the overloaded bus such that a controller of the overloaded bus controls the transmission cycle of a transmission message, and thus, even when the in-vehicle CAN bus is overloaded, communication in an in-vehicle network can be stably controlled without skipping transmission of the transmission message to a gateway.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a system and method for controlling internal bus load ratio of a vehicle, and a recording medium storing a computer readable program for executing the method. BACKGROUND OF THE INVENTION 1. Field of the Invention THE METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a vehicle communication system and a control method thereof, and more particularly, to a system for controlling a gate operation in an overloaded state of a CAN communication bus for a vehicle and a control method thereof.

Recently released vehicles are equipped with various in-vehicle communication networks for information exchange and status diagnosis among various controllers installed in the vehicle. In particular, most of the recently released vehicles are equipped with various vehicle safety systems and driver convenience systems, and accordingly, the amount of data transmitted and received on the in-vehicle communication network is rapidly increasing.

Accordingly, for medium and large-sized vehicles, a gateway is used to distribute the communication load. In order to cope with the communication load to be increased in the future, a faster communication method such as CAN-FD and Ethernet is being developed.

On the other hand, the gateway is a device that receives a message of a transmission CAN channel and delivers a message received on a receiving channel. When a different message occupies the CAN bus at the same time, a message having a higher priority is transmitted first . This transmission scheme is also applied when a retransmission occurs, so that transmission according to priority is performed.

However, when the communication load through the CAN bus increases, the CAN bus load ratio is increased, which may result in loss of high priority messages. Also, upon continued bus overload, the transmission of the gateway delivery message between the heterogeneous networks may be missed. However, there is a problem that the abnormality of the communication system due to the overload of the CAN bus is difficult to detect at the time of vehicle diagnosis and inspection.

KR 101524144 B1 KR 101580568 B1

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a system and method for stably controlling communication in a vehicle internal network without missing a gateway delivery message even when the CAN bus is overloaded in a vehicle The purpose is to provide.

In order to achieve the above object, a vehicle internal communication bus load rate control system according to the present invention includes a load ratio measurement unit, a message transmission unit, and a transmission period adjustment unit.

The load ratio measuring part measures the load ratio of the CAN bus in the vehicle and the message transmitting part transmits the warning message to the bus whose load ratio exceeds the overload reference value when an overload occurs in which the load ratio exceeds the preset overload reference value, And adjusts the transmission period of the transmission message transmitted from the controller to which the message is transmitted.

According to such a configuration, by sending a warning message to the overload bus when the CAN bus is overloaded, the controller of the overload bus adjusts the transmission period of the transmission message, so that even when the CAN bus overload of the vehicle is overloaded, It is possible to stably control the communication of the mobile terminal.

At this time, the warning message includes the information of the load factor, and the adjustment of the transmission period can be performed according to the information of the load factor. According to such a configuration, it is possible to more effectively cope with the overload situation on the bus by adjusting the transmission period according to the load rate.

The warning message may be transmitted when the difference between the time at which the load factor increases and the time at which the load factor decreases after the load factor is overloaded is equal to or longer than a preset time. At this time, the difference between the time at which the load factor increases and the time at which the load factor decreases The message of the preset format can be interrupted. According to this configuration, it is possible to deal with the overload situation on the bus more efficiently because the response can be made different depending on the degree of increase of the load factor.

The system may further include a failure record storage unit for storing a record of an overload occurrence. According to this configuration, it is possible to detect a communication system abnormality due to the overload of the CAN bus at the time of vehicle diagnosis and inspection.

In addition, the message transmission unit may transmit information of the normal state to the bus to which the warning message is transmitted when the load factor becomes the normal state where the load rate is equal to or less than the overload reference value. At this time, the message transmission unit can transmit the steady state information when the time after the load ratio becomes the steady state is equal to or longer than a preset time. According to this configuration, when the overload situation on the bus is resolved, the message transmission state can be quickly returned to the normal state, and the judgment error against the instantaneous load normal return can be prevented.

In addition, an invention in which the system is implemented in the form of a method and a recording medium recording a computer-readable program for executing the method are disclosed.

According to the present invention, a warning message is transmitted to an overload bus in the event of overload of the CAN bus, and the controller of the overload bus adjusts the transmission period of the transmission message, so that even when the CAN bus overload of the vehicle is overloaded, The communication can be stably controlled.

Also, by adjusting the transmission period according to the load factor, it becomes possible to more effectively cope with an overload situation on the bus.

In addition, it is possible to respond differently according to the degree of increase of the load factor, thereby enabling to more effectively cope with the overload situation on the bus.

In addition, a communication system abnormality due to the overload of the CAN bus can be detected at the time of vehicle diagnosis and inspection.

In addition, when the overload situation on the bus is resolved, the message transmission state can be quickly returned to the normal state, and the judgment error against the instantaneous load normal return can be prevented.

1 is a schematic block diagram of an in-vehicle communication bus load factor control system according to an embodiment of the present invention;
2 is a block diagram of an actual implementation of the intra-vehicle communication bus load factor control system of FIG.
3 is a schematic flow chart for performing the load factor control method of the in-vehicle communication bus load factor control system of FIG.
Fig. 4 is a schematic flow chart of the normal return judgment routine of Fig. 3; Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a schematic block diagram of an in-vehicle communication bus load factor control system according to an embodiment of the present invention. 1, the vehicle internal communication bus load factor control system 100 includes a load factor measurement unit 110, a message transmission unit 120, a transmission period adjustment unit 130, and a fault record storage unit 140.

In FIG. 1, each component of the in-vehicle communication bus load ratio control system 100 may be implemented by hardware alone, but may be generally implemented by hardware and hardware that operates on hardware.

The load ratio measuring unit 110 measures the load ratio of the in-vehicle CAN bus, and when the overload exceeding the preset overload reference value occurs, the message transmitting unit 120 transmits a warning message to the bus whose load ratio exceeds the overload reference value And the transmission period adjustment unit 130 adjusts the transmission period of the transmission message transmitted by the controller having received the warning message.

According to such a configuration, by sending a warning message to the overload bus when the CAN bus is overloaded, the controller of the overload bus adjusts the transmission period of the transmission message, so that even when the CAN bus overload of the vehicle is overloaded, It is possible to stably control the communication of the mobile terminal.

2 is a block diagram of an actual implementation of the intra-vehicle communication bus load factor control system of FIG. 2, the load factor measurement unit 110, the message transmission unit 120, and the failure record storage unit 140 of FIG. 1 are implemented in a gateway 210. The transmission period adjustment unit 130 includes a controller ≪ RTI ID = 0.0 > 220 < / RTI >

The CAN communication shown in FIG. 2 is a method for effective communication between the electronic modules of the vehicle, and the reliability of communication can be secured by applying the arbitration function through the gateway 210. At this time, the gateway 210 is an apparatus for intermediately routing communication between the plurality of nodes 220. In the vehicle, the gateway 210 performs routing to each domain channel bus during CAN communication.

 In FIG. 2, the gateway performs a function of converting and transmitting a CAN inter-disparity network message, and at the same time measures the load ratio of the communication network. At this time, when the load factor exceeds the overload reference value (for example, about 60%), the gateway 210 transmits a warning message to the bus, and each node (ECU) Increase the period to transmit.

At this time, the warning message includes the information of the load factor, and the adjustment of the transmission period can be performed according to the information of the load factor. 2, the gateway transmits the bus load ratio information to each node (ECU) 220, and each node (ECU) 220 receiving the warning message increases the period of the transmission message according to the bus load ratio information, can do. According to such a configuration, it is possible to more effectively cope with the overload situation on the bus by adjusting the transmission period according to the load rate.

The warning message may be transmitted when the difference between the time at which the load factor increases and the time at which the load factor decreases after the load factor is overloaded is equal to or longer than a preset time. At this time, the difference between the time at which the load factor increases and the time at which the load factor decreases The message of the preset format can be interrupted. According to this configuration, it is possible to deal with the overload situation on the bus more efficiently because the response can be made different depending on the degree of increase of the load factor.

The failure record storage unit 140 stores a record of the overload occurrence. In Figure 2, the gateway writes a failure code for overload to the EEPROM. According to this configuration, it is possible to detect a communication system abnormality due to the overload of the CAN bus at the time of vehicle diagnosis and inspection.

In addition, the message transmission unit 120 may transmit information of a normal state to a bus to which a warning message is transmitted when the load factor becomes a normal state which is equal to or less than the overload reference value. When the bus load ratio returns to normal, the gateway transmits information on the normal state to each node.

At this time, the message transmission unit 120 can transmit the steady state information when the time after the load rate becomes the steady state is equal to or longer than the predetermined time. According to this configuration, when the overload situation on the bus is solved, the message transmission state can be quickly returned to the normal state, and the judgment error against the instantaneous load normal return can be prevented.

3 is a schematic flow chart for performing the load factor control method of the in-vehicle communication bus load factor control system of FIG. Referring to FIG. 3, the gateway first performs a message / signal signal conversion (routing) function between heterogeneous networks (S110), and measures the CAN bus load ratio together with signal conversion (S120). At this time, it is possible to measure the bus load ratio per network by monitoring both the input (Rx) and output (Tx) CAN message frames (measuring the bus load ratio for each network such as B-CAN / C-CAN / P-CAN).

If the bus load ratio exceeds the overload reference value (60%) (S130), the gateway maintains the above steps S110 and S120. If the bus load ratio exceeds the overload reference value (60% (140), and determines whether the difference between the overload occurrence time and the normal return time is 50 ms or more (S150).

If it is more than 50 ms, the gateway sends a warning message to the corresponding bus and transmits information of a message preempting the load to each ECU (S160), and receives an ACK message from an ECU outputting a message preempting the load (S170).

When it is less than 50 ms, the single system related message such as multimedia is stopped (S180). In the case of less than 50 ms, a message having a high level of importance such as a message for system control is continuously transmitted. However, a message having a low level of importance such as a multimedia message is stopped.

Then, the load factor of the bus can be confirmed again (S185). If the overload reference value is still exceeded, a failure code for overload is recorded in the EEPROM (S190). If the bus load ratio drops below the overload reference value, the gateway can go back to the basic signal conversion process.

Then, the ECU that has received the warning message of the gateway increases the cycle of the overload message by two times (S200). When the bus load rate returns to normal, the normal state information is transmitted to each node and the normal return time is recorded S300).

4 is a schematic flow chart of the normal return determination routine of FIG. FIG. 4 shows an example of a case where the normal return determination time is 200 msec at a time of 20 ms and the bus load rate is maintained at about 60% or less.

The normal return of the bus overload state is confirmed (S310, S320), and the [bus normal] determination time is taken (S330, S340, S350) before the message transmission for the alarm release (S360). Such a configuration prevents a judgment error about instantaneous load normal return.

More specifically, when the bus load ratio is equal to or less than the overload reference value (about 60%), the internal count is incremented by 1 every 20 ms (S330). The CPU 200 counts 200 until it is determined that the bus is normal (S340).

When the internal count CNT exceeds 200, it is determined that the bus overload state is a normal return and the message of the [bus normal] state is sent to each node (ECU) (S360), and the fault code transits to the past state ).

When the bus load ratio exceeds the overload reference value (about 60%), the internal count is maintained, and the fault code is also determined as the current state (S370).

To summarize, the present invention relates to control of a gateway operation in an overloaded state of a CAN communication bus for a vehicle. If the load on the communication bus is high due to excessive traffic in the network or abnormal operation of the specific controller, the gateway signal conversion message may be missed and adversely affect the function of the vehicle system.

In order to solve such a problem, in the present invention, the gateway monitors the bus load state, and when the overload is determined, the communication overload state is transmitted to all the controllers in the vehicle system to stably control the communication.

Although the present invention has been described in terms of some preferred embodiments, the scope of the present invention should not be limited thereby but should be modified and improved in accordance with the above-described embodiments.

100: Vehicle communication bus load ratio control system
110:
120: message transmission unit
130: Transmission period adjustment section
140: Failure record storage unit
210: gateway
220:
220-1: first controller
220-2: second controller
220-3: third controller
220-4: fourth controller
220-5: fifth controller
220-6: sixth controller

Claims (15)

A system for controlling a CAN bus load rate between a gateway and a plurality of controllers,
A load ratio measuring unit for measuring a load ratio of the CAN bus;
A message transmission unit for transmitting a warning message to a bus whose load rate exceeds the overload reference value when an overload occurs in which the load rate exceeds a predetermined overload reference value; And
And a transmission period adjuster for adjusting a transmission period of a transmission message transmitted to the bus to which the warning message is transmitted according to the warning message.
The method according to claim 1,
Wherein the warning message includes information on the load factor,
Wherein the adjustment of the transmission period is performed in consideration of the information of the load factor.
The method of claim 2,
Wherein the warning message is transmitted when the difference between the time at which the load rate increases after the overload occurs and the time at which the load rate decreases is greater than or equal to a predetermined time.
The method of claim 3,
Wherein the message transmission unit suspends a message of a predetermined format when a difference between a time at which the load rate increases and a time at which the load rate decreases is shorter than a preset time.
The method of claim 4,
Further comprising a failure record storing unit for storing a record of the occurrence of the overload.
The method of claim 5,
Wherein the message transmission unit transmits the steady state information to the bus to which the warning message is transmitted when the load factor becomes a steady state which is equal to or less than the overload reference value.
The method of claim 6,
Wherein the message transmission unit transmits the steady state information when the time after the load factor becomes the steady state is equal to or greater than a predetermined time.
A method of controlling an in-vehicle communication bus load ratio of a control system for controlling a CAN bus load ratio between a gateway and a plurality of controllers,
A load factor measuring step of measuring a load factor of the CAN bus;
A warning message transmission step of transmitting an alarm message to the bus whose load rate exceeds the overload reference value when an overload occurs in which the load rate exceeds a predetermined overload reference value; And
And adjusting a transmission period of a transmission message transmitted to the bus to which the warning message is transmitted according to the warning message.
The method of claim 8,
Wherein the warning message includes information on the load factor,
Wherein the adjustment of the transmission period is performed in consideration of the information of the load factor.
The method of claim 9,
Wherein the warning message is transmitted when the difference between the time at which the load rate increases after the overload occurs and the time at which the load rate decreases is greater than or equal to a preset time.
The method of claim 10,
Wherein the message transmission step stops a message of a predetermined format when a difference between a time at which the load rate increases and a time at which the load rate decreases is shorter than a preset time.
The method of claim 11,
Further comprising a failure record storing step of storing a record of the occurrence of the overload.
The method of claim 12,
Wherein the message transmission step transmits normal state information to a bus to which the warning message is transmitted when the load factor becomes a normal state that is equal to or less than the overload reference value.
14. The method of claim 13,
Wherein the message transmission step transmits the steady state information when the time after the load factor becomes the steady state is equal to or greater than a predetermined time.
A recording medium on which a computer-readable program for executing the method of any one of claims 8 to 14 is recorded.

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