KR101481132B1 - Apparatus and method for synchronizing data output time in vehicle network - Google Patents

Abstract

The present invention suggests an apparatus and a method for synchronizing data output time in a vehicle network, capable of measuring transmission times spent to transmit data from a switch to nodes and synchronizing data output time between mutually different node pairs based on the transmission time. The apparatus for synchronizing the data output time according to the present invention comprises: a data transmission time measuring unit to measure the transmission times spent to transmit data from the switch to connect nodes constituting a local area network (LAN) with each other to the nodes; and a data transmission synchronization unit to synchronize the data output time between mutually different node pairs based on the transmission times.

Description

[0001] Apparatus and method for synchronizing data output time in a vehicle network [0002]

The present invention relates to an apparatus and method for synchronizing data output time between nodes constituting a network. More particularly, the present invention relates to an apparatus and method for synchronizing data output time between nodes constituting a vehicular network.

CAN (Controller Area Network) is a widely used automotive network. The transmission of CAN data is simultaneously transmitted to all the nodes connected to the network by using the broadcasting method, and the reception of data is determined by the receiving node. CAN is standardized to ISO 11519 for use at speeds up to 125 Kbps and standardized to ISO 19898 for utilization up to 1 Mbps.

However, various sensors such as camera sensor, radar sensor, and laser sensor are installed in the vehicle and various ADAS (Advanced Driver) such as ACC (Adaptive Cruise Control) / SCC (Smart Cruise Control), FCM (Forward Collision Mitigation) and AEB (Autonomous Emergency Braking) Assistance System) has been developed to increase the amount of data to be transmitted and received between in-vehicle devices. In order to actively cope with traffic accidents in ADAS-applied vehicles, a large amount of data must be processed in a short period of time. However, CAN has difficulties in handling large amounts of data in a short period of time because of its limited transmission speed.

Recently, Ethernet has been attracting attention as a car network. Ethernet is a network developed for a LAN (Local Area Network). Each device has a unique address and can transmit and receive data using this address. The maximum transmission speed is 1 Gbps. However, because Ethernet is generally designed based on Best Effort, it is difficult to predict the arrival time between different devices, which makes it impossible to synchronize output.

Korean Patent Publication No. 2013-0093811 describes an automotive Ethernet network system. However, this system proposes a car Ethernet for real-time networking with electronic control units (ECUs) and an Ethernet switch, but does not propose a solution for solving the above-mentioned problems.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and method for measuring transmission times required to transmit data from a switch to each node and synchronizing data output times between different pairs of nodes based on the transmission times, And to propose a method.

However, the objects of the present invention are not limited to those mentioned above, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

SUMMARY OF THE INVENTION The present invention has been made in order to achieve the above object, and it is an object of the present invention to provide a data transmission method and a data transmission method for measuring transmission times required for transmitting data from a switch connecting nodes constituting a LAN (Local Area Network) A time measuring unit; And a data transmission synchronization unit for synchronizing data output time between different pairs of nodes based on the transmission times.

Preferably, the data transmission synchronization unit comprises: a maximum transmission time detection unit detecting a maximum transmission time of the node pair based on the transmission times; A time stamp size determining unit for determining a size of a time stamp based on the maximum transmission time; A data transmission period determiner for determining a data transmission period based on the size of the time stamp; And a data transmission controller for synchronizing the data output time between different pairs of nodes based on the data transmission period.

Preferably, the data transmission period determination unit determines the maximum value of the size of the time stamp as the data transmission period.

Advantageously, said data transmission period precedes data in a packet transmitted between said pair of nodes.

Preferably, the nodes constituting the LAN in the data output time synchronization apparatus are end-nodes constituting an automotive Ethernet.

Preferably, the data transmission synchronization unit includes: a node pair detection unit that detects a node pair that requires the longest transmission time to transmit the data based on the transmission times; And a data transmission controller for controlling the transmission and reception of the data from the node pair requiring the longest transmission time to synchronize the data output time.

Preferably, the node pair detecting unit includes: a node pair generating unit for grouping a transmitting node to transmit the data and a receiving node to receive the data to generate a node pair; A data acquisition time calculating unit for calculating a data acquisition time required for each node pair to receive the data from the transmitting node based on the transmission times; And a data acquisition time comparing unit for comparing the data acquisition times and detecting a node pair that requires the most transmission time to transmit the data.

Preferably, the data transfer control unit comprises: a node pair sorting unit arranged to sort the node pairs in order of long transmission time based on the data acquisition times; And an order-based control unit for controlling the data to be transmitted and received according to the ordered sequence to synchronize the data output time.

Preferably, the order-based control unit reflects a time difference with a pair of senior nodes obtained by comparing data acquisition time when controlling the current-ranked node pair to transmit and receive the data.

In addition, the present invention provides a method of controlling a network, comprising: measuring transmission times for transmitting data from a switch connecting nodes constituting a local area network (LAN) to each node; And synchronizing the data output time between different pairs of nodes based on the transmission times.

Advantageously, synchronizing the data output time comprises: detecting a maximum transmission time of the node pair based on the transmission times; Determining a size of a timestamp based on the maximum transmission time; Determining a data transmission period based on the size of the time stamp; And synchronizing the data output time between different pairs of nodes based on the data transmission period.

Preferably, the step of determining the data transmission period determines the maximum value of the size of the time stamp as the data transmission period.

Advantageously, said data transmission period precedes data in a packet transmitted between said pair of nodes.

Preferably, the nodes configuring the LAN in the data output time synchronization method are end-nodes constituting an automotive Ethernet.

Advantageously, the step of synchronizing the data output time comprises: detecting a node pair that requires the most transmission time to transmit the data based on the transmission times; And synchronizing the data output time by controlling to transmit and receive the data from the node pair requiring the longest transmission time.

Preferably, the step of detecting the node pair includes: grouping a transmitting node to transmit the data and a receiving node to receive the data to generate a node pair; Calculating a data acquisition time required for the receiving node to receive the data from the transmitting node in each pair of nodes based on the transmission times; And comparing the data acquisition times to detect a node pair that requires the most transmission time to transmit the data.

Advantageously, synchronizing the data output time comprises: aligning the pairs of nodes in order of long transmission time based on the data acquisition times; And synchronizing the data output time by controlling transmission and reception of the data according to an ordered sequence.

Preferably, synchronizing the data output time by controlling transmission and reception of the data according to the ordered sequence comprises: comparing the data acquisition time when controlling the current node pair to transmit and receive the data, .

The present invention can obtain the following effects by measuring transmission times for transmitting data from a switch to each node and synchronizing data output times between different pairs of nodes based on the transmission times.

First, data output time can be synchronized between various devices in an automobile such as an actuator and an ECU (Electronic Control Unit).

Second, the efficiency of ADAS (Advanced Driver Assistance System) applied to vehicles such as ACC (Adaptive Cruise Control) / SCC (Smart Cruise Control), FCM (Forward Collision Mitigation) and AEB (Autonomous Emergency Braking)

1 is a conceptual diagram of an apparatus for synchronizing data output time according to a preferred embodiment of the present invention.
2 is a conceptual diagram illustrating an internal configuration of a data transmission synchronization unit according to the first embodiment in a data output time synchronization apparatus.
3 and 4 are reference views for further illustrating a data transmission synchronization unit according to the first embodiment.
5 is a conceptual diagram illustrating an internal configuration of a data transmission synchronization unit according to a second embodiment of the data output time synchronization apparatus.
6 is a flowchart illustrating a data output time synchronization method according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the preferred embodiments of the present invention will be described below, but it is needless to say that the technical idea of the present invention is not limited thereto and can be variously modified by those skilled in the art.

Ethernet is the most widely deployed LAN technology. Ethernet is originally developed by Xerox and developed by Xerox, DEC, and Intel, although it is now defined as a standard in the Institute of Electrical and Electronics Engineers (IEEE) 802.3.

Since the conventional Ethernet is competitively accessed using the CSMA / CD (Carrier Sense Multiple Access / Collision Detect) protocol defined in IEEE 802.3, the service frame of the upper layer is maintained as an Ethernet frame And transmits it. At this time, transmission is performed in the order of occurrence regardless of the type of the upper service frame. In other words, Ethernet is one of the most commonly used techniques to transfer data between different terminals or between users.

Such Ethernet is known as a technology that is not suitable for video transmission, which is sensitive to transmission time delay, because it carries CSMA / CD type transmission that gives equal priority to all Ethernet frames and transmits through competition.

In recent years, however, video transmission, which is sensitive to the transmission time delay, has been increasing and the proportion of the data transmission has increased. Accordingly, there have been proposed methods for eliminating the problem due to the transmission delay while maintaining the Ethernet method.

The present invention is designed to periodically transmit on the basis of time by measuring transmission times for transmitting data from a switch to each node and synchronizing data output times between different pairs of nodes based on the transmission times, Characterized in that the vehicle network is designed such that the arrival time is predictable within a predetermined time range.

1 is a conceptual diagram of an apparatus for synchronizing data output time according to a preferred embodiment of the present invention.

1, the data output time synchronization apparatus 100 includes a data transmission time measurement unit 110, a data transmission synchronization unit 120, a power supply unit 130, and a main control unit (not shown) 140).

The power supply unit 130 performs a function of supplying power to each configuration of the data output time synchronization apparatus 100. The main control unit 140 performs a function of controlling the overall operation of each configuration of the data output time synchronization apparatus 100.

The data transmission time measuring unit 110 measures transmission times required to transmit data from a switch connecting nodes constituting a vehicle network, that is, a LAN (Local Area Network), to each node.

The data transmission time measuring unit 110 may measure transmission times required to transmit data between two designated nodes.

In the data output time synchronization apparatus 100, the nodes constituting the LAN are end-nodes constituting the Ethernet for the vehicle.

The data transmission synchronization unit 120 performs a function of synchronizing data output times between different pairs of nodes based on the transmission times measured by the data transmission time measurement unit 110. [

The data transmission synchronization unit 120 may detect the maximum transmission time of the node pair based on the measured transmission times and synchronize the data output time based on the maximum transmission time. Also, the data transmission synchronization unit 120 may detect a node pair that takes the longest time to transmit data using the measured transmission times, and may synchronize the data output time based on the node pair. Hereinafter, the former and the latter will be described in more detail.

2 is a conceptual diagram illustrating an internal configuration of a data transmission synchronization unit according to the first embodiment in a data output time synchronization apparatus. 3 and 4 are reference views for further illustrating a data transmission synchronization unit according to the first embodiment. The following description refers to Fig. 2 to Fig.

2, the data transmission synchronization unit 120 includes a maximum transmission time detection unit 201, a time stamp size determination unit 202, a data transmission period determination unit 203, and a first data transmission control unit 204 .

The maximum transmission time detection unit 201 detects the maximum transmission time of the node pair based on the transmission times measured by the data transmission time measurement unit 110. [

Referring to FIG. 3, first, the data transmission time measurement unit 110 measures a transmission time required to transmit data from the Ethernet switch 320 to each end node. Then, the data transmission time between end nodes can be calculated. When the first end node 310 is the input node and the second end node 330 and the third end node 340 are the output nodes, T_en1 is from the first end node 310 to the third end node 330 T_en2 denotes a transmission time taken to transmit data from the first end node 310 to the fourth end node 340. [

The maximum transmission time detection unit 201 compares T_en1 and T_en2 to calculate the maximum transmission time T_MAX between the end nodes.

If (T_en1 > T_en2)

T_MAX = T_en1

else

T_MAX = T_en2

endif

The time stamp size determination unit 202 determines the size of the time stamp (Timestamp) based on the maximum transmission time detected by the maximum transmission time detection unit 201.

The time stamp size determination unit 202 determines the size of the time stamp that can correspond to T_MAX. If T_MAX is in the range of 0 to FF, 1 byte is determined as the size of the time stamp. If T_MAX is in the range of 0 to FFFF, 2 bytes are determined as the time stamp size.

The data transmission period determination unit 203 determines a data transmission period based on the size of the time stamp determined by the time stamp size determination unit 202. [

The data transmission period determiner 203 may determine the maximum value of the size of the time stamp as the data transmission period. In FIG. 3, the periodic transmission value T_TimeStamp may be determined as the maximum value of TimeStamp. For example, FF may be determined to be 1Byte, and FFFF may be determined to be 2Byte.

The first data transmission control unit 204 performs a function of synchronizing the data output time between the node pairs based on the data transmission period determined by the data transmission period determination unit 203. [

If T_TimeStamp is determined, T_TimeStamp is inserted in the Ethernet communication packet to communicate. Since the transmission time between the first end node 310 and the second end node 330 is within T_MAX and the transmission time between the first end node 310 and the third end node 340 is also within T_MAX, Synchronous transmission can be performed within each other.

FIG. 4 shows the structure of an Ethernet communication packet transmitted and received between a pair of nodes. In this embodiment, the data transmission period, T_TimeStamp 410, is located in front of the data in the packet.

On the other hand, the starting frame delimiter (SFD) in FIG. 4 indicates a byte synchronization for identifying a byte unit in a bit string and a frame synchronization bit for notifying that the byte sequence (DA + SA + ...) It means heat. DA means Destination Address and SA means Source Address.

5 is a conceptual diagram illustrating an internal configuration of a data transmission synchronization unit according to a second embodiment of the data output time synchronization apparatus.

Referring to FIG. 5, the data transmission synchronization unit 120 includes a node pair detection unit 410 and a second data transmission control unit 420.

The node pair detecting unit 410 detects a node pair that requires the longest transmission time to transmit data based on the transmission times measured by the data transmission time measuring unit 110. [

For this, the node pair detection unit 410 may include a node pair generation unit 411, a data acquisition time calculation unit 412, and a data acquisition time comparison unit 413.

The node-pair generating unit 411 performs a function of grouping a transmitting node to transmit data and a receiving node to receive data to generate a node pair.

The data acquisition time calculating unit 412 calculates a data acquisition time required for the receiving node to receive data from the transmitting node in each node pair based on the transmission times measured by the data transmission time measuring unit 110 .

The data acquisition time comparison unit 413 compares the data acquisition times calculated by the data acquisition time calculation unit 412 and detects a node pair that requires the longest transfer time to transfer data.

The second data transmission control unit 420 performs a function of controlling data transmission and reception from the node pair requiring the longest transmission time to synchronize the data output time.

For this, the second data transmission control unit 420 may include a node pair arrangement unit 421 and an order based control unit 422.

The node pair sorting unit 421 performs a function of sorting the node pairs in order of long transmission time based on the data acquisition times calculated by the data acquisition time calculating unit 412. [

The order-based control unit 422 performs a function to synchronize data output time by controlling transmission and reception of data according to an ordered sequence. Based control unit 422 may reflect the time difference with the senior node pair obtained by comparing the data acquisition time when controlling the current ranking node pair to send and receive data.

As described above, according to the present invention, the transmission time of a sensor or an actuator mounted on an end node is predicted by defining a time for exchanging predetermined data. That is, the present invention defines an area where a time stamp and a sequence number can be inserted into transmission data, and determines a time stamp range between output end nodes in an input end node so that outputs can be synchronized with each other .

Next, an operation method of the data output time synchronization apparatus 100 will be described. This method refers to an Ethernet network design method using periodic data transmission between end nodes in a network with an Ethernet switch. 6 is a flowchart illustrating a data output time synchronization method according to a preferred embodiment of the present invention.

First, the data transmission time measuring unit 110 measures transmission times required to transmit data from the switch connecting the nodes constituting the vehicular network to each node (S610).

Then, the data transmission synchronization unit 120 synchronizes the data output time between different pairs of nodes based on the transmission times measured by the data transmission time measurement unit 110. The following is a more detailed description.

The maximum transmission time detection unit 201 detects the maximum transmission time of the node pair based on the transmission times measured by the data transmission time measurement unit 110 (S620). Thereafter, the time stamp size determination unit 202 determines the size of the time stamp based on the maximum transmission time (S630). Thereafter, the data transmission period determination unit 203 determines a data transmission period based on the size of the time stamp (S640). Thereafter, the first data transfer control unit 204 synchronizes data output times between different pairs of nodes based on the data transfer period (S650).

The former is a case where the maximum transmission time of the node pair is detected based on the transmission times measured by the data transmission time measuring unit 110 and the data output time is synchronized based on the maximum transmission time. The present invention is not limited to this, and it is also possible to detect a node pair that takes the longest time to transmit data using the transmission times and to synchronize the data output time based on the node pair.

In the latter case, the following steps are performed in order after step S610.

The node pair generating unit 410 detects a node pair that requires the longest transmission time to transmit data based on the transmission times measured by the data transmission time measuring unit 110. [

The node-pair generating unit 410 generates a pair of nodes by grouping a transmitting node to which data is to be transmitted and a receiving node to which data is to be received. Then, based on the transmission times, And then comparing the data acquisition times, it is possible to detect a node pair that requires the longest transmission time to transmit the data.

Then, the second data transmission control unit 420 controls to transmit and receive data from the node pair requiring the longest transmission time, thereby synchronizing the data output time.

The second data transmission control unit 420 may arrange the node pairs in order of the long transmission time based on the data acquisition time and then control to transmit and receive data according to the ordered order so as to synchronize the data output time.

It is to be understood that the present invention is not limited to these embodiments, and all elements constituting the embodiment of the present invention described above are described as being combined or operated in one operation. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. In addition, such a computer program may be stored in a computer readable medium such as a USB memory, a CD disk, a flash memory, etc., and read and executed by a computer to implement an embodiment of the present invention. As the recording medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, and the like can be included.

Furthermore, all terms including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined in the Detailed Description. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (11)

A data transmission time measuring unit measuring transmission times taken to transmit data from a switch connecting nodes constituting an in-vehicle network to each node; And
A maximum transmission time detection unit for synchronizing data output time between different node pairs based on the transmission times, the maximum transmission time detection unit detecting a maximum transmission time of the node pair based on the transmission times; A time stamp size determining unit for determining a size of a time stamp based on the maximum transmission time; A data transmission period determiner for determining a data transmission period based on the size of the time stamp; And a data transmission control unit for synchronizing the data output time between different pairs of nodes based on the data transmission period,
Wherein the data output time synchronization device is configured to synchronize the data output time in the vehicle network. delete The method according to claim 1,
Wherein the data transmission period determination unit determines the maximum value of the size of the time stamp as the data transmission period. The method according to claim 1,
Wherein the data transmission period is located in front of data in a packet transmitted and received between the pair of nodes. The method according to claim 1,
Wherein the nodes configuring the in-vehicle network in the data output time synchronization apparatus are end-nodes constituting an Ethernet for a vehicle. The method according to claim 1,
Wherein the data transmission synchronization unit comprises:
A node-pair detecting unit for detecting a node pair that requires the longest transmission time to transmit the data based on the transmission times; And
A data transmission control unit for controlling the data transmission and reception from the node pair requiring the longest transmission time to synchronize the data output time,
Wherein the data output time synchronization device is configured to synchronize the data output time in the vehicle network. The method according to claim 6,
The node-pair detecting unit,
A node pair generating unit for grouping a transmitting node for transmitting the data and a receiving node for receiving the data to generate a node pair;
A data acquisition time calculating unit for calculating a data acquisition time required for each node pair to receive the data from the transmitting node based on the transmission times; And
A data acquisition time comparing unit for comparing a data acquisition time and detecting a node pair that requires the longest transmission time to transmit the data,
Wherein the data output time synchronization device is configured to synchronize the data output time in the vehicle network. 8. The method of claim 7,
Wherein the data transfer control unit comprises:
A node pair sorting unit for sorting the node pairs in order of long transmission time based on the data acquisition times; And
Based on a result of the order-based control to synchronize the data output time by controlling the transmission /
Wherein the data output time synchronization device is configured to synchronize the data output time in the vehicle network. 9. The method of claim 8,
Wherein the order-based control unit reflects a time difference with a pair of senior nodes obtained by comparing the data acquisition time when the pair of the current node is controlled to transmit and receive the data. Measuring transmission times for transmitting data from a switch connecting nodes constituting an intra-vehicle network to each node; And
Synchronizing data output times between different pairs of nodes based on the transmission times, the method comprising: detecting a maximum transmission time of a node pair based on the transmission times; Determining a size of a timestamp based on the maximum transmission time; Determining a data transmission period based on the size of the time stamp; And synchronizing the data output time between different pairs of nodes based on the data transmission period
Wherein the data output time synchronization method comprises the steps of: delete

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