KR101021914B1 - FlexRay Communication Transmission/Reception Method and Apparatus - Google Patents

Abstract

The present invention relates to a method and apparatus for transmitting / receiving flexray communications.

The present invention provides a payload generator for generating a payload for FlexRay communication; A compressor for compressing the payload; A frame generator that adds a header segment and a trailer segment to the compressed payload to generate a FlexRay frame; A frame encoder for generating a transmission frame by inserting a transmission start sequence and a byte start sequence into the FlexRay frame; And a transmitter for transmitting a transmission frame.

According to the present invention, it is possible to reduce the size of the physical frame transmitted in the FlexRay communication, not only to ensure the reliability and determinism of the data transmission in time-critical applications, but also to reduce the communication time to reduce the communication line efficiency It can increase.

FlexRay, Payload, Compression, FlexRay, Payload, Compression

Description

FlexRay Communication Transmission / Reception Method and Apparatus}

The present invention relates to a method and apparatus for transmitting / receiving flexray communications. More particularly, the present invention relates to a method and apparatus for increasing communication efficiency by reducing the size of a transmission frame in transmitting and receiving a transmission frame for FlexRay communication.

CAN (Controller Area Network) communication is mainly used as a communication technology for communication between devices provided in a vehicle. However, CAN communication is difficult to apply to time-deterministic and reliable data transmission due to limitations of carrier sense access / collation detection with arbitration on message priority (CSMA / CD + AMP).

As an alternative to such CAN communication, FlexRay communication, which adopts a time division multiple access (TDMA) method, is emerging. With the advent of FlexRay, the industry is actively moving to apply FlexRay to the backbone of Power Train, Chassis Control or in-vehicle networks.

In FlexRay communication, frame transmission must occur within a given slot within one communication cycle. In this case, the maximum frame size may be 263 bytes. When the frame is transmitted in the payload of the maximum size, the channel occupancy becomes excessive, thereby reducing communication efficiency.

In order to solve the above-mentioned problem, the present invention has a main object to ensure the determinism and stability of data transmission by compressing and transmitting a payload in a frame in a FlexRay communication.

In order to achieve the above object, the present invention provides a payload generator for generating a payload for FlexRay communication; A compressor for compressing the payload; A frame generator that adds a header segment and a trailer segment to the compressed payload to generate a FlexRay frame; A frame encoder for generating a transmission frame by inserting a transmission start sequence and a byte start sequence into the FlexRay frame; And a transmitter for transmitting a transmission frame.

In addition, according to another object of the present invention, generating a payload for the FlexRay communication; Compressing the payload; Generating a FlexRay frame by adding a header segment and a trailer segment to the compressed payload; Inserting a transmission start sequence and a byte start sequence into the FlexRay frame to generate a transmission frame; And transmitting a transmission frame.

In addition, according to another object of the present invention, a receiver for receiving a transmission frame; A frame decoder to restore the flexray frame by removing the transmission start sequence and the byte start sequence from the transmission frame; A frame separator that separates the recovered FlexRay frames into header segments, compressed payloads, and trailer segments; And a decompressor which decompresses the compressed payload to recover the payload.

In addition, according to another object of the present invention, a step of receiving a transmission frame; Restoring the flexlay frame by removing the transmission start sequence and the byte start sequence from the transmission frame; Separating the recovered flexlay frame into header segments, compressed payloads and trailer segments; And recovering the payload by decompressing the compressed payload.

As described above, according to the present invention, it is possible to reduce the size of the physical frame transmitted in the FlexRay communication, not only to ensure the reliability and reliability of data transmission in time-critical applications, but also to occupy the communication line Can reduce the communication efficiency.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different 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, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but between components It will be understood that may be "connected", "coupled" or "connected".

1 is an exemplary diagram showing a cycle configuration of the FlexRay communication.

Flexlay communication is defined to use a time division multiple access (TDMA) scheme for static segments and a flexible time-division multiple access (FTDMA) scheme for dynamic segments. FlexRay communication transmits data with a size of 0 ~ 254 bytes to the network in the static slot method and the dynamic slot method based on the priority so that a specific node sends only the time allocated to it. . This FlexRay communication supports time division and priority-based multiple access methods simultaneously, enabling flexible network configuration, and the network topology has bus and star shapes, and single channel and dual channel. ) May be applied.

1 shows an example in which a dual channel is applied, and a number such as '3' shown in '3a', '1b', and '2c' is indicated according to a node transmitting a message. Letters such as 'b' may be displayed depending on the message being sent.

Figure 2 is an exemplary view showing the structure of a FlexRay frame.

The frame of the FlexRay includes a header segment, a payload segment, and a trailer segment.

In this case, the header segment includes an indicator, a frame ID field, a payload length field, a header cyclic redundancy check field, and a cycle count field. do. The frame ID in the Frame ID field is used to identify the frame and to prioritize the event triggered frame. The payload length in the Payload Length field is used to specify the size of the payload transmitted in the frame. Header CRC The header CRC of the field is used to detect an error during transmission, and the cycle count of the cycle count field is a counter value that is incremented each time the communication period begins.

The payload segment is composed of a plurality of data fields, in which actual data to be transmitted through a frame is inserted. The trailer segment consists of three Cyclic Redundancy Check Fields, each of which is assigned a bit to detect an error.

In the structure of the FlexRay frame as shown in FIG. 2, the maximum frame size may be 263 bytes. When the FlexRay frame is transmitted in the payload of the maximum size, the occupancy of the channel may be excessive, thereby reducing communication efficiency. .

3 is a block diagram schematically illustrating a flexray communication transmission apparatus according to an embodiment of the present invention.

The FlexRay communication transmission device 300 according to an embodiment of the present invention includes a payload creator 310, a compressor 320, a frame creator 330, a frame encoder 340. ) And a transmitter 350. The flexray communication transmission device 300 or each component may be embodied as a communication device for exchanging data in control devices, sensors, and actuators mounted in a vehicle. Here, the communication device may include a memory for storing hardware such as a host processor, a Flexray controller, a bus guardian, and a program for operating the hardware.

Payload generator 310 generates payloads for flexlay communication. That is, the payload generator 310 generates a payload to be transmitted through the flexray communication.

Compressor 320 compresses the payload. That is, the compressor 320 compresses the payload generated by the payload generator 310 to reduce the data size of the payload. Here, the compressor 320 may compress the payload by using a lossless compression technique. The lossless compression technique may include a run-length coding (RLC) algorithm, a temporary-ziv coding (LZC) algorithm, and a lampwise lamp (LZW). -Ziv-Welch) may be one or more of the. Therefore, the compressor 320 may compress the payload by reducing the size of an iterative sequence ('1' or '0' that repeats continuously) using the lossless compression technique.

The frame generator 330 adds a header segment and a trailer segment to the compressed payload to generate a FlexRay frame. That is, the frame generator 330 generates the FlexRay frame by adding the header segment and the trailer segment as shown in FIG. 2 to the payload compressed by the compressor 320.

The frame encoder 340 generates a transmission frame by inserting a transmission start sequence and a byte start sequence into the FlexRay frame. That is, the frame encoder 340 inserts a transmission start sequence and a byte start sequence into the FlexRay frame generated by the frame generator 330 to generate the final transmission frame transmitted through the communication medium.

The transmitter 350 transmits a transmission frame. That is, the transmitter 350 converts the transmission frame generated by the frame encoder 340 into an electrical signal and transmits the electrical signal through a communication line.

4 is a flowchart illustrating a method for transmitting a FlexRay communication according to an embodiment of the present invention.

The FlexRay communication transmission device 300 generates a payload for the FlexRay communication (S410), compresses the generated payload (S420), and adds a header segment and a trailer segment to the compressed payload to display the FlexRay frame. Generate (S430), insert a transmission start sequence and byte start sequence into the FlexRay frame to generate a transmission frame (S440), and transmit the transmission frame (S450).

In operation S420, the FlexRay communication transmission apparatus 300 may compress the payload using a lossless compression technique, and the lossless compression technique may include a run-length coding (RLC) algorithm, a temporary-ziv coding (LZC) algorithm, and an LZW. (Lampel-Ziv-Welch) may be one or more of the algorithm.

Typically, in FlexRay communication, since the payload occupies about 97% of the transmission frame and the compression ratio of the lossless compression technique is about 1/2 to 1/3, compressing the payload according to an embodiment of the present invention Therefore, the size of the transmission frame can be reduced by about 35% to 51%. Therefore, it can be seen that if the payload is reduced in the transmission frame of the FlexRay where the payload is the largest, the size of the entire transmission frame can be significantly reduced.

Therefore, in transmitting one frame for FlexRay communication, the occupancy time of the communication line can be reduced to about 1/2 to 1/3, thereby improving the overall communication efficiency of the system using the FlexRay communication. Not only can it be improved, but more advantageous results can be obtained in the transmission of time-determined data.

As described above, the transmission frame generated by compressing the payload using a lossless compression technique or the like is transmitted to a flex ray communication receiving apparatus to be described later through a communication line, and included in the transmission frame in the flex ray communication receiving apparatus. Compressed payloads can be decompressed to utilize the recovered payloads.

5 is a block diagram schematically illustrating an apparatus for receiving a FlexRay communication according to an embodiment of the present invention.

The apparatus 500 for receiving a FlexRay communication according to an embodiment of the present invention includes a receiver 510, a frame decoder 520, a frame separator 530, and a decompressor 540. It may be configured to include. The FlexRay communication receiver 500 or each component may be implemented as a communication device for exchanging data between control devices, sensors, and actuators mounted on a vehicle. Here, the communication device may include a memory for storing hardware such as a host processor, a Flexray controller, a bus guardian, and a program for operating the hardware.

Receiver 510 receives a transmission frame. That is, the receiver 510 receives a frame converted into an electrical signal from the flex-ray communication transmission device 300 or the like through a communication line or the like (S510).

The frame decoder 520 restores the flexlay frame by removing the transmission start sequence and the byte start sequence from the transmission frame. That is, the frame decoder 520 restores the flexlay frame including the compressed payload by removing the transmission start sequence and the byte start sequence from the transmission frame received by the receiver 510.

Frame separator 530 separates the recovered FlexRay frame into header segments, compressed payloads and trailer segments. That is, the frame separator 530 separates the FlexRay frame reconstructed by the frame decoder 520 in each segment unit, and extracts a header segment, a payload segment including a compressed payload, and a trailer segment.

The decompressor 540 decompresses the compressed payload to recover the payload. That is, the decompressor 540 decompresses the compressed payload of the payload segment extracted and separated by the frame separator 530 to restore the payload. Here, the decompressor 540 may restore the payload by performing a reverse process of the lossless compression technique on the compressed payload. The lossless compression technique may be one or more of an RLC algorithm, an LZC algorithm, and an LZW algorithm. The lossless compression technique may use the same compression technique as the lossless compression technique used to compress the payload in the flexray communication transmission apparatus 300.

To this end, the FlexRay communication transmission device 300 and the FlexRay communication receiving device 500 may compress the payload and decompress the compressed payload using a lossless compression scheme previously promised. In addition, when the lossless compression scheme is not set in advance between the FlexRay communication transmitter 300 and the FlexRay communication receiver 500, the FlexRay communication transmitter 300 may include a plurality of header segments or payload segments. Identification information for identifying which lossless compression scheme is compressed may be inserted into one of the fields, and the FlexRay communication receiving apparatus 500 extracts the identification information from the corresponding field in the received transmission frame to prevent any losslessness. It is possible to identify whether a compression technique was used and to decompress the compressed payload using the identified lossless compression technique.

6 is a flowchart illustrating a method for receiving a FlexRay communication according to an embodiment of the present invention.

When receiving the transmission frame (S610), the FlexRay communication receiving apparatus 500 restores the FlexRay frame by removing the transmission start sequence and the byte start sequence from the transmission frame (S620), and restores the restored FlexRay frame to the header segment, The compressed payload and trailer segments are separated (S630), and the compressed payload is decompressed to restore the payload (S640). The payload restored as described above may be distributed and utilized to a place requiring data included in the payload.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented in one independent hardware, each or all of the components may be selectively combined to perform some or all functions combined in one or a plurality of hardware. It may be implemented as a computer program having a. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program is stored in a computer readable storage medium, which is read and executed by a computer, thereby implementing embodiments of the present invention. The storage medium of the computer program may include a magnetic recording medium, an optical recording medium, a carrier wave medium, and the like.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be inherent unless specifically stated otherwise, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms used generally, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is an exemplary diagram showing a cycle configuration of a flexray communication;

2 is an exemplary view showing the structure of a FlexRay frame;

3 is a block diagram briefly showing a flex-ray communication transmission apparatus according to an embodiment of the present invention,

4 is a flowchart for explaining a flexray communication transmission method according to an embodiment of the present invention;

FIG. 5 is a block diagram schematically illustrating an apparatus for receiving a FlexRay communication according to an embodiment of the present invention; FIG.

6 is a flowchart illustrating a method for receiving a FlexRay communication according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

300: FlexRay communication transmitter 310: Payload generator

320: compressor 330: frame generator

340: frame encoder 350: transmitter

500: FlexRay communication receiver 510: Receiver

520: frame decoder 530: frame separator

540: decompressor

Claims (9)

A payload generator for generating payloads for flexlay communication; A compressor for compressing the payload; A frame generator generating a FlexRay frame by adding a header segment and a trailer segment to the compressed payload; A frame encoder for generating a transmission frame by inserting a transmission start sequence and a byte start sequence into the flexlay frame; And A transmitter for transmitting the transmission frame, And identification information for identifying a scheme in which the compressor compresses the payload is inserted into one field of the header segment. The method of claim 1, wherein the compressor, And compressing the payload using a lossless compression technique. The method of claim 2, wherein the lossless compression technique, And a compression technique using one of a Run-Length Coding (RLC) algorithm, a Lempel-Ziv Coding (LZC) algorithm, and a Lamp-Ziv-Welch (LZW). The method of claim 2, wherein the compressor, And compressing the payload by reducing the size of an iterative sequence of the payload using the lossless compression technique. Generating a payload for the flexlay communication; Compressing the payload; Adding a header segment and a trailer segment to the compressed payload to generate a flexlay frame; Generating a transmission frame by inserting a transmission start sequence and a byte start sequence into the flexlay frame; And Transmitting the transmission frame; And identification information for identifying a technique of compressing the payload in the compressing step is inserted in any one field of the header segment. A receiver for receiving a transmission frame; A frame decoder for recovering a FlexRay frame by removing a transmission start sequence and a byte start sequence from the transmission frame; A frame separator that separates the recovered FlexRay frame into header segments, compressed payloads and trailer segments; And A decompressor for decompressing the compressed payload to restore the payload, And identification information for identifying a technique of compressing the payload is inserted into one field of the header segment. The method of claim 6, wherein the decompressor, And recovering the payload by performing a reverse process of a lossless compression technique on the compressed payload. The method of claim 7, wherein the lossless compression technique, And a compression technique using one of a Run-Length Coding (RLC) algorithm, a Lempel-Ziv Coding (LZC) algorithm, and a Lamp-Ziv-Welch (LZW). Receiving a transmission frame; Restoring a flexlay frame by removing a transmission start sequence and a byte start sequence from the transmission frame; Separating the recovered flexlay frame into header segments, compressed payloads, and trailer segments; And Decompressing the compressed payload to restore the payload, And identification information for identifying a technique of compressing the payload is inserted into any one field of the header segment.

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