KR102241999B1 - Gateway for automotive Ethernet application and System and Method for synchronizing sensor and node using the same - Google Patents

Abstract

The present invention relates to a gateway for vehicle ethernet application, which can be more stable and secure real-time performance by time synchronization of a sensor and a node based on a CAN (FD) and the ethernet using a gateway, and to a device and a method for synchronizing a sensor and a node using the same. The device of the present invention comprises: CAN (FD) nodes having a bus type topology, and connected to a gateway through a bus line; ethernet nodes connected to an ethernet switch to transmit and receive data in a peer-to-peer communication scheme; and a gateway connected to the bus line including the CAN (FD) nodes and the ethernet switch, and performing a role of exchanging data of two networks by implementing time synchronization between the CAN (FD) nodes and the ethernet nodes.

Description

A gateway for automotive Ethernet application and a device and method for synchronizing sensors and nodes using the same {Gateway for automotive Ethernet application and System and Method for synchronizing sensor and node using the same}

The present invention relates to a vehicle network technology, and specifically, a gateway for application of Ethernet for a vehicle to ensure more stable and real-time by synchronizing time of a sensor and node based on CAN (FD) and Ethernet using a gateway and It relates to an apparatus and method for synchronizing sensors and nodes using the same.

In order to recognize and control road conditions in real time in recent years, more sensors such as Camera, LIDAR, and RADAR and Electronic Control Units (ECUs) have been installed than existing vehicles, and the amount of data exchanged within the vehicle has increased exponentially.

In the vehicle network technology, protocols such as CAN (Controller Area Network), LIN (Local Interconnect Network), and FlexRay are applied due to the increase in data exchanged between vehicle ECUs.

However, due to the recent rapid development of autonomous driving and information communication technologies such as ADAS technology and V2X, the existing IVN cannot avoid technological changes. In particular, in order to use sensors for recognizing external environment information for autonomous driving, such as Lidar, Radar, and Camera, a communication technology that guarantees a very high bandwidth is essential.

Ethernet is one of the communication technologies suitable for solving this problem, and many studies are currently being conducted to apply it to vehicles. However, in order to communicate with a conventional vehicle network, a gateway that matches each other's protocol is essential.

In an autonomous driving controller that integrates and processes various sensor information to perform the control logic of the vehicle, a difference in control performance occurs according to the presence or absence of time information at the time when the sensors measure external information.

This is because the sensors of the unsynchronized network transmit information measured at different times to the controller. Therefore, at this time when ADAS and autonomous driving technologies are studied and applied, the importance of time synchronization of sensors and controllers of vehicles is more emphasized.

In the conventional CAN network synchronization method, the master node transmits a time clock to the slave node. The slave node replaces the received master's time clock with its own clock and repeats it at a certain period.

However, this method does not take into account the delay required for transmission from the master node to the slave node, resulting in an error in time synchronization.

Meanwhile, due to the development of autonomous driving technology, the number of sensors installed in the vehicle is increasing dramatically, and the development and application of an integrated controller to process external information measured by the sensor, control the vehicle stably, and ensure real-time performance. This is actively going on.

However, there is no technology for time synchronization between a conventional vehicle network, CAN-based sensor and controller, and Ethernet-based sensor and controller.

In particular, IEEE 1588 is a representative standard for network time synchronization, but since IEEE 1588 supports time synchronization of Ethernet networks, it is required to develop a separate time synchronization technology for vehicle networks that mainly use CAN or CAN FD. Has become.

Korean Patent Registration No. 10-2048685 Korean Patent Registration No. 10-1596759 Republic of Korea Patent Publication No. 10-2019-0002906

The present invention is to solve the problem of the vehicle network technology of the prior art, by using a gateway to synchronize the time of CAN (FD) and Ethernet-based sensors and nodes to ensure more stable and real-time Ethernet for vehicles. An object of the present invention is to provide a gateway for application and an apparatus and method for synchronizing sensors and nodes using the same.

The present invention implements IEEE 1588-based time synchronization technology using a gateway connecting CAN (FD) and Ethernet in a vehicle network, and provides a gateway for applying Ethernet for a vehicle to compensate for the protocol conversion time occurring in the gateway. An object of the present invention is to provide an apparatus and method for synchronizing a sensor and a node used.

The present invention introduces the IEEE 1588 standard PTP procedure for time synchronization in an Ethernet-based network and implements a PTP mechanism in a CAN (FD) network to minimize time synchronization errors by performing time synchronization between nodes. An object of the present invention is to provide a gateway for vehicle Ethernet application, and an apparatus and method for synchronizing sensors and nodes using the same.

The present invention uses a gateway that enables communication by converting messages for time synchronization between CAN (FD) and Ethernet nodes, which are different networks, and enables precise time synchronization by compensating for processing delay. An object of the present invention is to provide a gateway for applying Ethernet for vehicles and an apparatus and method for synchronizing sensors and nodes using the same.

The present invention enables time synchronization between heterogeneous networks and performs time synchronization between an integrated controller of an autonomous vehicle, a sensor, and an ECU, so that the vehicle controller knows the measurement time of sensor data and reflects it in the control logic. An object of the present invention is to provide a gateway for application of Ethernet for vehicles, which can make a great contribution to improving real-time performance and stability, and an apparatus and method for synchronizing sensors and nodes using the same.

The present invention enables time synchronization between heterogeneous networks, thereby performing time synchronization between an integrated controller of an autonomous vehicle, a sensor, and an ECU, thereby performing an essential role in data logging of a storage medium for vehicle failure diagnosis and analysis of the cause of an accident. An object of the present invention is to provide a gateway for applying Ethernet for vehicles, and an apparatus and method for synchronizing sensors and nodes using the same.

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

A gateway for applying Ethernet for a vehicle according to the present invention to achieve the above object includes a first message reception confirmation unit that checks whether a Sync message transmitted from a master node is received; If a Sync message is received, it converts it into a CAN message. CAN message conversion unit; A first residence delay calculation unit that calculates the residence delay α consumed when converting the CAN message; a first message transmission unit that stores α in the CAN_Sync_message converted into a CAN message and transmits it to the destination; transmission from the slave node A second message reception confirmation unit that checks whether a CAN_Delay_request message has been received; an Ethernet message conversion unit that converts the CAN_Delay_request message into an Ethernet message; a second residence delay calculation unit that calculates the residence delay β required when converting an Ethernet message; and an Ethernet message. And a second message transmission unit that stores β in the converted Delay_request message and transmits it to a destination.

Here, when a Follow_up or Delay_response message transmitted from the master node is received, it is converted into a CAN message, transmitted to the destination, and the Ethernet to CAN message conversion time α is calculated. Therefore, in the case of Follow_up and Delay_response messages, separate conversion time is calculated. It is characterized by not doing.

In addition, the gateway is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch, and performs a role of exchanging data of two networks by implementing time synchronization between the CAN (FD) node and the Ethernet node. .

The device for synchronizing a sensor and a node using a gateway for application of Ethernet for a vehicle according to the present invention for achieving another object has a bus topology and is connected to the gateway through a bus line CAN (FD) nodes; Ethernet switch Ethernet nodes that are connected to and transmit and receive data in a peer-to-peer communication method; a bus line composed of CAN(FD) nodes and an Ethernet switch are connected, and time synchronization between the CAN(FD) node and the Ethernet node is implemented. It characterized in that it includes; a gateway that performs a role of exchanging data of the branch network.

Here, in order to compensate for the processing delay occurring in the gateway, the processing delay is defined as a time α for converting an Ethernet message to a CAN message and a time β for converting a CAN message to an Ethernet message, α and β are defined as the time from when the PTP message is received from the gateway to just before it is transmitted to the destination after conversion, and the gateway corrects α and β measured in the timestamp value of the PTP message transmitted by the master and slave. It performs a task, and through this, it is characterized by reducing time synchronization errors.

In addition, in order to reduce the time synchronization error, in order to apply the time synchronization method on the Ethernet network through the PTP protocol of IEEE 1588 to the CAN network that can transmit up to 8 bytes of data, reduce the timestamp field value of the PTP message and reduce the number of seconds. The timestamp field value of the PTP message consisting of 10 bytes, consisting of 6 bytes indicating the unit and 4 bytes indicating the nanosecond unit, is applied to the CAN message format by deleting the upper 2 bytes of the second unit that do not affect the system control. do.

A method for synchronizing a sensor and a node using a gateway for application of Ethernet for a vehicle according to the present invention to achieve another object is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch, and is connected to a CAN (FD) node. The Ethernet node selected as the master of time synchronization slaves the sync message at time T1 for time synchronization in the vehicle network including the gateway that performs the role of exchanging data between the two networks by implementing time synchronization between Ethernet nodes. Transmitting to the node and receiving the time T2 by the slave; The master node sends the follow up message with time T1 back to the slave node, and the slave node checks the time T1 and T2 at the time of receiving the follow up message; The node sends a delay request message to the master at time T3 and the master receives it at time T4; the master node sends the time T4 to the slave by putting the delay response message in, and finally the slave node sends the time T1, T2, T3, And determining T4 and calculating propagation delay.

Here, in the step of calculating the propagation delay,

으로 계산하고, α는 Ethernet 프레임이 CAN 메시지로 변환하는데 소요되는 시간으로, 게이트웨이가 Ethernet 프레임을 수신 완료한 시점에서 변환된 CAN 메시지가 전송되기 직전의 시간으로 정의되고, 게이트웨이는 α를 측정하고 마스터 노드에서 전송되는 sync 메시지에 저장하고, β는 CAN 메시지가 Ethernet 프레임으로 변환되는데 소요되는 시간으로, CAN 메시지 수신이 완료된 시점에서 변환된 Ethernet 프레임이 전송되기 직전의 시간으로 정의되고, 게이트웨이는 delay request 메시지에 β를 저장하는 것을 특징으로 한다.

And α is the time it takes for the Ethernet frame to be converted into a CAN message, and is defined as the time just before the converted CAN message is transmitted at the time when the gateway completes receiving the Ethernet frame, and the gateway measures α and the master It is stored in the sync message transmitted from the node, and β is the time it takes for the CAN message to be converted into an Ethernet frame, defined as the time just before the converted Ethernet frame is transmitted when the CAN message is received, and the gateway is a delay request. It is characterized by storing β in the message.

A method for synchronizing a sensor and a node using a gateway for application of Ethernet for a vehicle according to the present invention to achieve another object is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch, and is connected to a CAN (FD) node. In order to synchronize the time of the Ethernet-based master node in the vehicle network including the gateway that performs the role of exchanging data between the two networks by implementing time synchronization between Ethernet nodes, the Ethernet master node transmits a Sync message to the slave node. And storing the time t1 in the memory buffer; storing t1 in the Follow_up message to inform the slave node of the transmission time t1 of the Sync message and transmitting it to the slave node; If there is a Delay_request message transmitted from the slave node Including: storing the message reception time t4 and the residence time β included in the Delay_request message, which is required for converting the CAN message into the Ethernet message at the gateway; inserting t4 and β in the Delay_response message and transmitting it to the slave; including Characterized in that.

A method for synchronizing a sensor and a node using a gateway for application of Ethernet for a vehicle according to the present invention to achieve another object is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch, and is connected to a CAN (FD) node. Receiving a Sync message transmitted from a master node for time synchronization of a CAN-based slave node in a vehicle network including a gateway that implements time synchronization between Ethernet nodes and exchanges data of two networks. ;The slave node stores the sync message received times t2 and α in the memory buffer, and waits until the CAN_Follow_up message is received; If a CAN_Follow_up message is received, the transmission time t1 of the Sync message stored in the message is stored in the memory buffer. Storing; Transmitting a CAN_Delay_request message at time t3 and waiting for a CAN_Delay_response message to be received; When receiving a CAN_Delay_response message, storing reception times t4 and β included in the message in a memory buffer; Acquired time factor and calculating a delay time using (t1, t2, t3, t4, α, β) and correcting an offset clock using the delay time.

Here, α denotes a residence delay required to convert an Ethernet message into a CAN message in the gateway, and the CAN_Follow_up and CAN_Delay_response messages denote a time synchronization message in the CAN network.

A method for synchronizing a sensor and a node using a gateway for application of Ethernet for a vehicle according to the present invention to achieve another object is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch, and is connected to a CAN (FD) node. For time synchronization of the gateway, which is responsible for exchanging data between two networks by implementing time synchronization between Ethernet nodes, confirming whether a Sync message transmitted from the master node is received; If a Sync message is received, it is a CAN message. Converting to and calculating the required residence delay α; Storing α in CAN_Sync_message converted into CAN message and transmitting it to the destination; When a Follow_up or Delay_response message transmitted from the master node is received, it is converted into a CAN message. And transmitting to the destination; converting the CAN_Delay_request message transmitted from the slave node into an Ethernet message and calculating the required residence delay β; storing β in the Delay_request message converted to the Ethernet message and transmitting it to the destination. It characterized in that it includes;

The gateway for applying Ethernet for a vehicle according to the present invention as described above, and an apparatus and method for synchronizing sensors and nodes using the same have the following effects.

First, time synchronization between CAN (FD) and Ethernet-based sensors and nodes is performed using a gateway to ensure more stable and real-time performance.

Second, it implements IEEE 1588-based time synchronization technology by using a gateway connecting CAN (FD) and Ethernet in the vehicle network, and efficiently compensates for the protocol conversion time occurring in the gateway.

Third, by introducing the IEEE 1588 standard PTP procedure for time synchronization in an Ethernet-based network, the PTP mechanism is implemented in a CAN (FD) network, and time synchronization errors can be minimized by performing time synchronization between nodes.

Fourth, for time synchronization between CAN (FD) and Ethernet nodes, which are different networks, a gateway that enables communication by converting messages is used, and processing delay can be compensated for precise time synchronization. do.

Fifth, by enabling time synchronization between heterogeneous networks, the vehicle controller knows the measurement time of the sensor data and reflects it in the control logic by performing time synchronization between the integrated controller of the autonomous vehicle, the sensor, and the ECU. It can make a big contribution to improving the performance and stability.

Sixth, by enabling time synchronization between heterogeneous networks and performing time synchronization between the integrated controller of the autonomous vehicle, the sensor, and the ECU, it can play an essential role in data logging of the storage medium for vehicle failure diagnosis and accident cause analysis. To be able to.

1 is a configuration diagram of a gateway for applying Ethernet for a vehicle according to the present invention and an apparatus for synchronizing sensors and nodes using the same
2 is a detailed configuration diagram of a gateway for applying Ethernet for a vehicle according to the present invention
3 is a flowchart showing a time synchronization procedure of a vehicle network to which a gateway is applied
4 is a block diagram showing the structure of a PTP message based on a CAN network
5 is a flow chart showing a time synchronization process of an Ethernet-based master node
6 is a flow chart showing a time synchronization process of a CAN-based slave node
7 is a flow chart showing a time synchronization process of a gateway
8 is a graph showing a result of time synchronization of a vehicle network using a gateway according to the present invention

Hereinafter, a preferred embodiment of a gateway for applying Ethernet for a vehicle according to the present invention and an apparatus and method for synchronizing sensors and nodes using the same will be described in detail as follows.

Features and advantages of a gateway for application of a vehicle Ethernet according to the present invention and an apparatus and method for synchronizing sensors and nodes using the same will become apparent through detailed description of each embodiment below.

1 is a configuration diagram of a gateway for applying Ethernet for a vehicle according to the present invention and an apparatus for synchronizing sensors and nodes using the same.

A gateway for applying Ethernet for a vehicle according to the present invention and an apparatus and method for synchronizing sensors and nodes using the same enable synchronization between heterogeneous networks using a gateway, and compensate for processing delays occurring in the gateway for time synchronization. It minimizes errors and applies a time synchronization procedure based on IEEE international standards to facilitate high compatibility and technology implementation.

To this end, the present invention introduces a PTP procedure of the IEEE 1588 standard for time synchronization in an Ethernet-based network, implements a PTP mechanism in a CAN (FD) network, and performs time synchronization between nodes, thereby minimizing time synchronization errors. It may include a configuration that allows.

The present invention uses a gateway that enables communication by converting messages for time synchronization between CAN (FD) and Ethernet nodes, which are different networks, and enables precise time synchronization by compensating for processing delay. It may include a configuration that allows you to

The present invention includes a configuration in which the vehicle controller knows the measurement time of sensor data and reflects it in the control logic by performing time synchronization between the integrated controller of the autonomous vehicle, the sensor and the ECU by enabling time synchronization between heterogeneous networks. I can.

In the present invention, a domain communicating via CAN (FD), a domain communicating via Ethernet, and a gateway are configured, and a network node constituting each domain includes a PTP module.

Here, PTP is a technology related to time synchronization of an Ethernet network in the IEEE 1588 standard, and each node is composed of a master/slave.

For time synchronization, the master node and the slave node transmit and receive a specific message according to the PTP protocol, and use the time to calculate a propagation delay when the message is transmitted. The slave uses the calculated propagation delay and the time sent from the master to change its own clock to the same as the master.

In a vehicle network environment including a gateway, it is necessary to compensate for the processing delay occurring in the gateway.

The processing delay is expressed as the time α for converting an Ethernet message to a CAN message and β for converting a CAN message to an Ethernet message.

At this time, α and β are defined as the time from the point when the PTP message is completely received by the gateway until immediately before it is transmitted to the destination after conversion.

The gateway corrects the measured α and β in the timestamp value of the PTP message transmitted by the master and the slave, thereby reducing the time synchronization error.

A gateway for applying Ethernet for a vehicle according to the present invention having such a configuration, and an apparatus and method for synchronizing sensors and nodes using the same, are a gateway that enables data exchange between CAN (FD) and Ethernet, which is a vehicle network, and CAN through the gateway. This is a technology for realizing time synchronization between (FD) nodes and Ethernet nodes.

1 shows a gateway 200 that enables data exchange between CAN (FD) and Ethernet, which is a vehicle network, and a CAN (FD) node 100, an Ethernet node 400, and an Ethernet switch 300 with time synchronization. Is shown.

The present invention has a bus topology and is connected to a CAN (FD) node 100 connected to the gateway 200 through a bus line, and the Ethernet switch 300 to transmit and receive data in a peer-to-peer communication method. It is connected to the bus line consisting of the Ethernet node 400 and the CAN (FD) node 100 and the Ethernet switch 300, and exchanges data of two networks by realizing time synchronization between the CAN (FD) node and the Ethernet node. It includes a gateway 200 that performs a role of.

CAN (FD), one of the vehicle networks, has a bus-type topology, and in the case of vehicle Ethernet, it is connected to a switch through a peer-to-peer communication method to transmit and receive data between each other.

The gateway is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch to exchange data between two networks.

A detailed configuration of a gateway for applying Ethernet for a vehicle according to the present invention is as follows.

2 is a detailed configuration diagram of a gateway for applying Ethernet for a vehicle according to the present invention.

As shown in FIG. 2, the gateway for applying Ethernet for a vehicle according to the present invention includes a first message reception confirmation unit 21 that checks whether a Sync message transmitted from a master node is received, and if a Sync message is received, it is converted into a CAN message. A CAN message conversion unit 22 that converts, a first residence delay calculation unit 23 that calculates residence delay α consumed when converting a CAN message, and stores α in the CAN_Sync_message converted into a CAN message and then transmits it to the destination. A first message transmission unit 24, a second message reception confirmation unit 25 for checking whether a CAN_Delay_request message transmitted from the slave node has been received, an Ethernet message conversion unit 26 for converting a CAN_Delay_request message into an Ethernet message, and And a second residence delay calculation unit 27 that calculates the residence delay β required when converting the Ethernet message, and a second message transmission unit 28 that stores β in the Delay_request message converted into an Ethernet message and transmits it to a destination. .

Here, when a Follow_up or Delay_response message transmitted from the master node is received, it is converted into a CAN message and transmitted to the destination.

Since the Ethernet to CAN message conversion time α was calculated earlier, separate conversion time is not calculated for Follow_up and Delay_response messages.

The time synchronization procedure of the vehicle network to which the gateway according to the present invention is applied will be described as follows.

3 is a flowchart showing a time synchronization procedure of a vehicle network to which a gateway is applied.

3 shows a time synchronization procedure and a processing delay occurring inside the gateway when a gateway is applied in a vehicle network composed of CAN (FD) and Ethernet nodes.

The time synchronization procedure in the vehicle network is as follows.

First, as shown in FIG. 3, the Ethernet node selected as the master for time synchronization transmits a sync message to the slave node at time T1, and the slave receives it at time T2. (S301)

Next, the master node sends the follow up message with the time T1 back to the slave node, and at the time of receiving it, the slave node can know the times T1 and T2 (S302).

The slave node transmits a delay request message to the master at time T3, and the master receives it at time T4 (S303).

Finally, the master puts the time T4 in the delay response message and sends it to the slave, and finally the slave can know the times T1, T2, T3, and T4, and calculate the propagation delay through Equation 1. (S304)

However, Equation 1 can be applied in an environment where the propagation delay generated when transmitting from the master node to the slave node and the propagation delay generated when transmitting from the slave to the master are the same.

In the case of a vehicle network including a gateway, the time to convert CAN to Ethernet and the time to convert Ethernet to CAN is different, so it is necessary to correct the processing delay that occurs in the gateway.

The α expressed in FIG. 3 is the time taken for the Ethernet frame to be converted into a CAN message, and is defined as the time immediately before the converted CAN message is transmitted at the time when the gateway completes receiving the Ethernet frame.

The gateway measures α and stores it in the sync message transmitted from the master node.

On the contrary, β, which is the time it takes for CAN message to be converted into Ethernet frame, is the time just before the converted Ethernet frame is transmitted at the time when CAN message reception is completed, and the gateway stores β in the delay request message.

The processing delay calculation equation for time synchronization in the vehicle network including the gateway is as in Equation 2.

The structure of the CAN network-based PTP message is as follows.

4 is a block diagram showing the structure of a PTP message based on a CAN network.

The IEEE 1588 PTP protocol is a method of performing time synchronization on an Ethernet network. In order to apply it to a CAN network that can transmit up to 8 bytes of data, the timestamp field value of the PTP message must be reduced.

The timestamp of the PTP message is 10 bytes in total, and the upper 2 bytes of the second unit that do not affect the system control are deleted and applied to the CAN message format.

4 shows a structure in which an Ethernet-based PTP message is converted into a CAN message format.

In the Ethernet-based PTP message, the timestamp field is composed of 6 bytes indicating the unit of seconds and 4 bytes indicating the unit of nanoseconds, and a total of 10 bytes.

On the other hand, there is a problem that the data field for storing the timestamp in CAN is up to 8 bytes and cannot contain all the time.

Therefore, in the present invention, in order to convert an Ethernet-based PTP message into a CAN network, the unit of a second in the timestamp field is reduced to 4 bytes.

When the second unit is reduced to 4 bytes, it is impossible to display the time in annual units, but this can be corrected through the system internal storage device or a separate communication protocol.

The time synchronization process of the Ethernet-based master node is as follows.

5 is a flow chart showing a time synchronization process of an Ethernet-based master node.

First, the Ethernet master node transmits the Sync message to the slave node and stores the time t1 in the memory buffer (S501).

Second, to inform the slave node of the transmission time t1 of the Sync message, t1 is stored in the Follow_up message and then transmitted to the slave node (S502).

Next, if there is a Delay_request message transmitted from the slave node (S503), the reception time t4 of the message and β included in the Delay_request message are stored (S504).

Here, β denotes the residence time required to convert CAN messages into Ethernet messages in the gateway.

Finally, after inserting t4 and β in the Delay_response message, it is transmitted to the slave (S505).

The time synchronization process of the CAN-based slave node is as follows.

6 is a flow chart showing a time synchronization process of a CAN-based slave node.

First, time synchronization of the slave node starts with receiving a Sync message transmitted from the master node (S601).

The slave node stores t2 and α, which are the times the Sync message was received, in the memory buffer (S602), and waits until the CAN_Follow_up message is received (S603).

Here, α means the residence delay required to convert the Ethernet message into a CAN message in the gateway, and the CAN_Follow_up message means a time synchronization message in the CAN network.

If the CAN_Follow_up message is received, the transmission time t1 of the Sync message stored in the message is stored in the memory buffer (S604).

Next, a CAN_Delay_request message is transmitted at time t3 (S605), and waits until a CAN_Delay_response message is received (S606).

Here, the CAN_Follow_up and CAN_Delay_response messages mean time synchronization messages in the CAN network.

When the CAN_Delay_response message is received, the reception times t4 and β included in the message are stored in the memory buffer (S607).

The delay time is calculated through Equation 2 using the last acquired time elements (t1, t2, t3, t4, α, β), and the offset clock is corrected using this (S608).

The time synchronization process of the gateway is as follows.

7 is a flow chart showing a time synchronization process of a gateway.

First, it is checked whether or not the Sync message transmitted from the master node has been received (S701).

If a Sync message is received, it is converted into a CAN message (S702), and the residence delay α consumed at this time is calculated (S703).

Then, after storing α in CAN_Sync_message converted to CAN message, it is transmitted to the destination (S704).

Next, when the Follow_up or Delay_response message transmitted from the master node is received (S705), it is converted into a CAN message (S706) and transmitted to the destination (S707).

Since the Ethernet to CAN message conversion time α was calculated earlier, separate conversion time is not calculated for Follow_up and Delay_response messages.

Finally, when the CAN_Delay_request message transmitted from the slave node is received (S708), it is converted into an Ethernet message (S709), and the residence delay β required at this time is calculated (S710).

Then, β is stored in the Delay_request message converted to an Ethernet message and transmitted to the destination (S711).

8 is a graph showing a time synchronization result of a vehicle network using a gateway according to the present invention.

8 shows a time error when time synchronization is applied in a topology in which an Ethernet node selected as a master and a CAN node selected as a slave are connected 1:1 using a gateway.

In order to evaluate the performance of the gateway for application of the vehicle Ethernet according to the present invention and the device and method for synchronizing sensors and nodes using the same, a topology consisting of one CAN node, one Ethernet node, and a gateway was constructed.

After each node performs time synchronization, the two nodes share the same time, generate a trigger signal through the I/O pin at the same time, and measure the time deviation of the two trigger signals using an oscilloscope.

As a result of repeatedly measuring the time deviation of these two signals seven times, it was confirmed that a time error of about 5.5us occurred.

This means that the error in time synchronization can be minimized by compensating for the processing delay occurring in the gateway.

The gateway for applying Ethernet for a vehicle according to the present invention described above, and an apparatus and method for synchronizing sensors and nodes using the same, introduce a PTP procedure of the IEEE 1588 standard for time synchronization in an Ethernet-based network, and change the PTP mechanism to CAN ( FD) It is implemented in a network to minimize time synchronization errors by performing time synchronization between nodes.

As described above, it will be understood that the present invention is implemented in a modified form without departing from the essential characteristics of the present invention.

Therefore, the specified embodiments should be considered from a descriptive point of view rather than a limiting point of view, and the scope of the present invention is shown in the claims rather than the above description, and all differences within the scope equivalent thereto are included in the present invention. It will have to be interpreted.

100. CAN(FD) Node
200. Gateway
300. Ethernet switch
400. Ethernet node

Claims (12)

A first message reception confirmation unit that checks whether or not a Sync message transmitted from the master node is received;
A CAN message conversion unit for converting the Sync message into a CAN message if it is received;
A first residence delay calculation unit that calculates residence delay α required when converting a CAN message;
A first message transmission unit for storing α in CAN_Sync_message converted into a CAN message and then transmitting it to a destination;
A second message reception confirmation unit that checks whether a CAN_Delay_request message transmitted from the slave node has been received;
An Ethernet message conversion unit converting a CAN_Delay_request message into an Ethernet message;
A second residence delay calculation unit that calculates a residence delay β required when converting an Ethernet message;
And a second message transmission unit that stores β in the Delay_request message converted into an Ethernet message and transmits it to a destination. The method of claim 1, wherein when a Follow_up or Delay_response message transmitted from a master node is received, it is converted into a CAN message and transmitted to a destination,
Gateway for automotive Ethernet application, characterized in that separate conversion times are not calculated for Follow_up and Delay_response messages because α, which is the Ethernet to CAN message conversion time, is calculated. The method of claim 1, wherein the gateway,
It is connected to a bus line composed of CAN (FD) nodes and an Ethernet switch, and implements time synchronization between the CAN (FD) node and the Ethernet node to exchange data between two networks. Gateway for. CAN (FD) nodes having a bus topology and connected to a gateway through a bus line;
Ethernet nodes connected to an Ethernet switch to transmit and receive data in a peer-to-peer communication method;
Including; a bus line composed of CAN (FD) nodes and a gateway that is connected to an Ethernet switch and performs a role of exchanging data of two networks by implementing time synchronization between the CAN (FD) node and the Ethernet node,
In order to compensate for the processing delay occurring in the gateway, the processing delay is defined as the time α for converting an Ethernet message to a CAN message and a time β for converting a CAN message to an Ethernet message, and α and β is defined as the time from when the PTP message is received from the gateway to just before it is transmitted to the destination after conversion, and the gateway corrects the measured α and β in the timestamp value of the PTP message transmitted by the master and slave. A device for synchronizing a sensor and a node using a gateway for applying Ethernet for a vehicle, characterized in that the time synchronization error is reduced through this. delete The method of claim 4, wherein in order to reduce a time synchronization error,
In order to apply the method of time synchronization on the Ethernet network through the PTP protocol of IEEE 1588 to the CAN network that can transmit up to 8 bytes of data, reduce the timestamp field value of the PTP message
The timestamp field value of the PTP message consisting of 10 bytes, consisting of 6 bytes indicating the second unit and 4 bytes indicating the nanosecond unit, is applied to the CAN message format by deleting the upper 2 bytes of the second unit that do not affect the system control. A device for synchronizing sensors and nodes using a gateway for automotive Ethernet application. In a vehicle network including a bus line composed of CAN (FD) nodes and a gateway that is connected to an Ethernet switch and performs time synchronization between the CAN (FD) node and the Ethernet node to exchange data between the two networks. For time synchronization,
The Ethernet node selected as the master of time synchronization transmits a sync message to the slave node at time T1 and the slave receives it at time T2;
The master node sends the follow-up message to the slave node again with the time T1, and the slave node checks the times T1 and T2 at the time of receiving the follow-up message;
The slave node transmits a delay request message to the master at time T3 and the master receives it at time T4;
The master node puts the time T4 in the delay response message and sends it to the slave, and finally the slave node checks the times T1, T2, T3, and T4, and calculates the propagation delay. Method for synchronizing sensors and nodes using a gateway for The method of claim 7, wherein in the step of calculating propagation delay,

Is calculated as,
α is the time it takes for the Ethernet frame to be converted into a CAN message, defined as the time immediately before the converted CAN message is transmitted at the time when the gateway completes receiving the Ethernet frame, and the gateway measures α and transmits it from the master node. save it in the sync message,
β is the time it takes for the CAN message to be converted into an Ethernet frame, defined as the time immediately before the converted Ethernet frame is transmitted at the time when CAN message reception is completed, and the gateway stores β in the delay request message. A method for synchronizing sensors and nodes using a gateway for automotive Ethernet application. In a vehicle network including a bus line composed of CAN (FD) nodes and a gateway that is connected to an Ethernet switch and performs time synchronization between the CAN (FD) node and the Ethernet node to exchange data between the two networks. For time synchronization of the Ethernet-based master node,
Transmitting a Sync message from the Ethernet master node to a slave node and storing the time t1 in a memory buffer;
Storing t1 in the Follow_up message and transmitting it to the slave node in order to inform the slave node of the transmission time t1 of the Sync message;
If there is a Delay_request message transmitted from the slave node, storing a reception time t4 of the message and a residence time β required to convert the CAN message into an Ethernet message at the gateway, which is included in the Delay_request message;
Inserting t4 and β in the Delay_response message and then transmitting it to the slave; method for synchronizing a sensor and a node using a gateway for applying Ethernet for a vehicle. In a vehicle network including a bus line composed of CAN (FD) nodes and a gateway that is connected to an Ethernet switch and performs time synchronization between the CAN (FD) node and the Ethernet node to exchange data between the two networks. For time synchronization of CAN-based slave nodes,
Receiving a Sync message transmitted from the master node;
The slave node stores t2 and α, which are times when the Sync message is received, in a memory buffer, and waits until a CAN_Follow_up message is received;
If the CAN_Follow_up message is received, storing the transmission time t1 of the Sync message stored in the message in a memory buffer;
Transmitting a CAN_Delay_request message at time t3 and waiting until a CAN_Delay_response message is received;
Storing the reception times t4 and β included in the message in a memory buffer when a CAN_Delay_response message is received;
Computing the delay time using the acquired time elements (t1, t2, t3, t4, α, β) and correcting the offset clock using the calculated delay time; Method for synchronizing sensors and nodes using. The method of claim 10, wherein α means a residence delay required for converting an Ethernet message into a CAN message in the gateway,
The CAN_Follow_up, CAN_Delay_response message means a time synchronization message in a CAN network. A method for synchronizing a sensor and a node using a gateway for applying Ethernet for a vehicle. For time synchronization of the gateway, which is connected to a bus line composed of CAN(FD) nodes and an Ethernet switch, and performs time synchronization between the CAN(FD) node and the Ethernet node, exchanging data from two networks,
Checking whether a Sync message transmitted from the master node is received;
Converting the Sync message into a CAN message if it is received, and calculating the required residence delay α;
Storing α in CAN_Sync_message converted into a CAN message and transmitting it to a destination;
When a Follow_up or Delay_response message transmitted from a master node is received, converting it into a CAN message and transmitting it to a destination;
Converting the CAN_Delay_request message transmitted from the slave node into an Ethernet message and calculating the required residence delay β when receiving the CAN_Delay_request message;
Storing β in the Delay_request message converted into an Ethernet message and transmitting it to a destination; method for synchronizing a sensor and a node using a gateway for applying Ethernet for a vehicle.

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