KR101301078B1 - System, Device and Method for Controlling FlexRay Network - Google Patents

Abstract

The present invention relates to a FlexRay network control system, apparatus, and method, wherein a FlexRay network control system according to an embodiment of the present invention includes a plurality of nodes and a bus connecting the plurality of nodes to each other, Each of the nodes of s constitute a signal including a static area of a predetermined size and a dynamic area determined to be dynamic, and include a control unit for controlling the transmitted signal to be transmitted to neighboring nodes through a bus. If the size of the data to be recorded in the static area exceeds the size allocated to the static area, the controller is configured to configure the signal by recording the excess data in the dynamic area.

Description

System, Device and Method for Controlling FlexRay Network

The present invention relates to a FlexRay network control system, apparatus, and method, and more particularly, when transmitting information in a FlexRay Network, for example, data that exceeds the size of a pre-allocated static segment can be dynamically changed in a corresponding communication period. The present invention relates to a FlexRay network control system, an apparatus, and a method for carrying a data load in a segment.

Today's vehicles contain a myriad of controls, sensors, actuators, controllers, and application systems. Commonly used wiring harnesses to connect these separate systems together require cables of only a few kilometers in length and tens of kilograms in weight, which is a significant part of the overall vehicle weight and manufacturing cost. Will occupy. The solution to this problem is to connect all systems to one common network bus consisting of one or two wires running around the vehicle. This not only reduces the weight of the wiring itself, but also makes it possible to reduce the total manufacturing cost of the vehicle with low-cost network interface chips.

To this end, today's cars use the Controller Area Network (CAN) protocol. CAN was developed by Robert Bosch GmbH of Germany in the late 1980s and was designed for communication between microcontrollers. The communication method used in CAN is a carrier sense multiple access (CSMA) method such as Ethernet, which requires a node connected to the bus to wait until there is no data transmitted on the bus in order to transmit data. Such unpredictability of entering a bus may cause a delay in data transmission rate in consideration of an increase in data transmission amount due to an increase in electronic devices in a vehicle.

Flexure was developed to make up for the shortcomings of CAN. The flexlay operates in a time division multiple access (TDMA) manner. Nodes connected to the bus are assigned a fixed time slot that allows exclusive entry rights. The time slots are repeated at defined intervals so that the time the data is on the bus is accurately calculated and predictable for bus entry. This advantage prevents delays in data rates such as CAN. In addition, the FlexRate's bit rate is up to 10 MBit / s, which can theoretically be 10 times faster than CAN (up to 1MBit / s).

In a safety-controlled control system such as an active safety vehicle (ASV), when a driver performs an operation such as steering or braking related to actual driving, the control signal is sent to a destination within a predetermined time. Transmission must be guaranteed, but there are limitations with existing CAN networks. Therefore, in order to guarantee the operation safety, the trend is to use a FlexRay that is accurately determined the bus entry and transmission time of the message.

However, in the conventional FlexRay, since the period and data size of the static segment and the dynamic segment are predetermined according to the specification, a system error occurs when the data transmitted / received between nodes in the vehicle exceeds the preset data size. there is a problem. There is also an additional cost associated with redesigning the FlexRay network to reduce errors in these systems.

Embodiments of the present invention provide a FlexRay network control system, apparatus, and method that can flexibly process data when transmitting information in a FlexRay network, even if the information exceeds the data storage space of a static segment without system error or network redesign. The purpose is to provide.

The FlexRay network control system according to the embodiment of the present invention includes a plurality of nodes; And a bus connecting the plurality of nodes to each other, each of the plurality of nodes constituting a signal including a static area of a predetermined size and a dynamic area determined to be dynamic. And a controller for controlling the configured signal to be transmitted to a neighboring node through the bus, wherein the controller is configured to transmit excess data to the dynamic area when the size of data to be recorded in the static area exceeds the size allocated to the static area. The signal is configured by recording in an area.

The control unit configures the signal divided into a plurality of time slots during one cycle time according to a FlexRay communication period, and the plurality of time slots are the static area, the dynamic area, and a symbol window area. And a network idle time, wherein the plurality of nodes are synchronized with the controller to receive and process the signal in a time slot corresponding to each node.

In addition, the FlexRay network control device according to an embodiment of the present invention, in the control device connected to the FlexRay network, the flex signal is a signal including a static area of a predetermined size and a dynamic area determined to be dynamic (dynamic) Transmitter for transmitting to each node connected to the ray network; And configures the signal and provides the signal to the transmission unit, and determines whether the size of data to be recorded in the static area exceeds the size allocated to the static area. Characterized in that it comprises a control unit for configuring.

The control unit may add an indicator for notifying whether the dynamic area is used in the static area when the excess data is recorded in the dynamic area.

Furthermore, a method of controlling a flexlay network according to an embodiment of the present invention includes determining whether a size of data to be recorded in a static area exceeds a size allocated to the static area; If the size of the data exceeds the size allocated to the static region, distributing the data into the static region and the dynamic region to construct a signal; And transmitting the configured signal to a neighboring node.

The configuring of the signal may include recording the data corresponding to the size allocated to the static area in the static area and recording the excess data in the dynamic area to configure the signal.

When the excess data is recorded in the dynamic area, an indicator for notifying whether the dynamic area is used is added to the static area.

The configuring of the signal may include configuring the signal divided into a plurality of time slots during one cycle time according to a FlexRay communication period, wherein the plurality of time slots comprise the static area, the dynamic area, and a symbol window area. It is characterized by being divided into network idle time.

1 is a diagram illustrating a flexray network control system according to an embodiment of the present invention;
FIG. 2 is a view for explaining a FlexRay communication cycle applied to the system of FIG. 1;
3 is a block diagram illustrating the structure of a node shown in FIG.
4 is a block diagram illustrating a detailed structure of a controller of FIG. 3;
5 is a diagram illustrating a method of controlling a flexlay network according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a diagram illustrating a flexray network control system according to an embodiment of the present invention.

As shown in FIG. 1, a FlexRay network control system according to an embodiment of the present invention includes a plurality of nodes 100 and a bus 110.

The system for the FlexRay, which is a next-generation in-vehicle network, may include a plurality of nodes 100 connected to a common bus 110 to communicate with each other. In this case, the plurality of nodes 100 represents a myriad of control devices, sensors, actuators, controllers, application systems, and the like in the vehicle.

According to an embodiment of the present invention, each node 100 connected to such a common bus 110 preferably operates in a TDMA manner, and nodes connected to the bus 110 according to the specification of FlexRay have exclusive access rights. Allocated fixed time slots are allowed. To do this, a program or application generated by an automobile manufacturer or a major supplier must meet network standards. In addition, each node 100 is implemented by mixing a core static frame and a dynamic frame through a predetermined communication period to provide static and dynamic data in a predefined space. As will be described in detail later with respect to the communication cycle, since a static or dynamic segment is meant to include a header, payload (or data frame), trailer, in the embodiment of the present invention it can be understood that the frame refers to the payload , A static region may be understood to refer to a static segment or payload.

Furthermore, each node 100 must guarantee safety in the FlexRay communication process. For this purpose, in the embodiment of the present invention, for example, in order to load and transmit data in a static segment when transmitting data to a node 100 located nearby, It is determined whether the data exceeds the allocated size. If the data exceeds the determined size, the data is loaded on the data load space of the dynamic segment of the period. In this case, the node 100 may insert additional information, that is, an indicator, into the static segment so that the neighboring node 100 may know that the static segment data is loaded and transmitted in the dynamic segment in the corresponding period. In this case, the additional information is preferably inserted in the header. Also, based on the above, in addition to determining the size of the transmitted data, each node 100 checks the additional information of the data when there is received data, and adds whether variable loading of the data has been performed. It may be determined that the received data can be processed. In this case, variable loading means repeating a process using or not using a dynamic area every communication cycle.

The bus 110 is a kind of communication line that allows a plurality of nodes 100 to perform FlexRay communication. In FIG. 1, the bus 110 illustrates a hybrid network forming a hybrid topology in which a relatively simple multidrop bus and a star network are integrated. However, the embodiment of the present invention may be applied to various networks such as a multidrop bus and a star network as well as a hybrid network, and thus the present invention will not be limited to a specific network. Here, the star network means to support a 'star' configuration composed of individual links connected to a central active node.

FIG. 2 is a diagram for describing a FlexRay communication cycle applied to the system of FIG. 1.

The FlexRay communication cycle is a fundamental element of the media access structure within the FlexRay. The period of the cycle is fixed when the network is designed, but it is generally preferred to be in the order of 1-5 ms.

As shown in Fig. 2, there are four main parts of the communication period. Static segments are reserved slots for deterministic data arriving over a fixed period of time, and dynamic segments are used for a wide variety of event-based data that operates in a CAN-like manner and does not require determinism. The symbol window is also used for signaling to maintain and start the network, and the network downtime is known as the so-called "quiet" time, which is used to maintain synchronization between node clocks. The smallest practical unit of time in a FlexRay network is a macrotick. The FlexRay controller actively synchronizes itself and adjusts the local clock so that macroticks occur at the same point for all nodes in the network. Although macrotick is configurable for a particular network, it is usually 1 microsecond, and since macroticks are synchronized, data that depends on macroticks is also synchronized.

More specifically, a static segment is a space of periods dedicated to scheduling multiple time-triggered frames. Segments are divided into slots, each slot holding a reserved data frame. If each slot occurs in time, the secured Electronic Control Unit (ECU) has the opportunity to send data to these slots. Once that time has passed, the ECU must wait until the next cycle to transmit data in the slot. Since the exact point in time in the cycle is known, the data is deterministic and the program knows exactly how old the data is. This is very useful when calculating control loops that rely on consistent spatial data. A real flexlay network can contain up to dozens of static slots. If the ECU is offline or not transmitting data, the slot remains open and not used by other ECUs.

When it comes to dynamic segments, most embedded networks have fewer high-speed messages and a lot of slower, less critical networks. In order to accommodate a wide range of data without slowing down the FlexRay period in an excessive number of static slots, dynamic segments sometimes allow for transmitted data. Since segments are of fixed length, there is a limit to the amount of fixed data placed in dynamic segments per period. In order to prioritize data, minislots are previously assigned to each data frame that can be transmitted in the dynamic segment. Minislots are generally macroticks (eg microseconds) long. High priority data receives a minislot near the beginning of the dynamic frame. When a minislot occurs, the ECU has a brief opportunity to broadcast the frame. If you don't broadcast, you lose space in dynamic frames and you get the next minislot. This process moves along the minislot until the ECU chooses to broadcast the data. When data is broadcast, future minislots must wait for the ECU to complete the data broadcast. When the dynamic frame window ends, the low priority minislot must then wait for the next cycle of broadcast opportunities. The final result of the dynamic segment is similar to the arbitration structure used in CAN.

Symbol windows are often used to maintain and track special periods, such as cold-start periods. Most high level applications do not work with symbol windows.

Network downtime is the length that a predefined ECU knows about. The ECU uses this downtime to make adjustments for drift that may have occurred during the previous cycle.

As for the frame format, each slot of a static or dynamic segment has a FlexRay frame. As briefly mentioned above, a frame is divided into three segments: a header, a payload, and a trailer.

The header may consist of 5 bytes, or 40 bits in length. Fields such as 5 bits of status bits, 11 bits of frame ID, 7 bits of payload length, 11 bits of header CRC, and 6 bits of cycle count Include. Here, the frame ID is a slot to which a frame should be transmitted and is used to prioritize an event triggered frame. The payload length includes the number of characters transmitted in the frame, and the header CRC is used to detect errors during transmission. The cycle count includes the value of the counter and increments each time the communication cycle begins.

The payload contains the actual data that the frame transmits. The length of a FlexRay payload or data frame is up to 127 characters, or 254 bytes, which is more than 30 times that of CAN.

The trailer has three 8-bit CRCs for error detection.

Now let's look briefly at frame-to-signal conversion. FlexRay data is represented in bytes. Most applications require data to be represented as actual decimal values in units, scaling, limits, and so on. By adopting one or more bits / bytes from the FlexRay frame and applying scaling and offsets, a signal can be obtained that is useful for actual parameter communication between ECUs. Most ECU programs operate on FlexRay data as signals, leaving the driver or low-level communication protocol to convert the signals into raw frame data.

The average car has hundreds to thousands of signals. Since the scaling, offset, definition, and position of these signals can change, the FlexRay network stores these definitions in the FIBEX database that defines the network. This makes it easy to write a program for the FlexRay network. This is because designers can simply refer to signal names in code. The compiler or driver then extracts the most recent scaling and offset information when the program is updated for the ECU or test system.

3 is a block diagram illustrating the structure of a node shown in FIG. 1, and FIG. 4 is a block diagram showing a detailed structure of the controller of FIG.

3 and 4 together with FIG. 1, a node (or control device) according to an embodiment of the present invention may include the interface unit 300, the control unit (or signal processing unit) 310, and the data transmission / reception unit 320. It may include some or all of them. In the embodiments of the present invention will be described as including all in order to facilitate a sufficient understanding of the invention.

The interface unit 300 is, for example, a connection for applying a background debug mode (BDM) tool, and may not be substantially included in all nodes 100. The BDM connection unit may be used to provide a standard method for inspecting the node 100 by applying any tool, and may be used to store or write a specific program for performing the FlexRay communication. In the embodiment of will not be specifically limited to such use.

The controller 310 may generate data according to the request, that is, when the driver in the vehicle performs an operation such as steering or braking related to actual driving, in order to perform the FlexRay communication. According to the ray specification, each segment is repeated periodically by dividing into a static segment that can use only a predetermined time and a dynamic segment that can be freely used within a time constraint. In this process, the controller 310 first determines whether or not the size allocated to the static area is exceeded before loading the corresponding data in the static segment, more precisely, in the corresponding period. It can be loaded and transmitted in the dynamic area. The control unit 310 transmits data to the surrounding node 100 by loading data variably by repeating such an operation every communication period.

In order to perform the above functions, the controller 310 may include some or all of the determination unit 400, the signal variable unit 410, and the microprocessor 420 as shown in FIG. 4. (Not shown) may be further included. Of course, in the embodiment of the present invention is described as including all, the determination unit 400 and the signal variable unit 410 may be configured to be integrated with each other.

For example, when the data is generated, the determination unit 400 determines whether the size of the generated data exceeds the data loading space of the static region for the flexlay communication period. For example, the determination unit 400 may compare the size of the data generated substantially with a reference value for the data load of the static area. For this purpose, the determination unit 400 may include a comparator, and the reference value It can be linked to a storage unit for storing.

As a result of the determination by the determination unit 400, when it is determined that the data loading space of the static area is exceeded in the corresponding period, the microprocessor 420 controls the signal variable unit 410 to determine the data loading space of the static area in the signal configuration. Any excess data will be loaded into the dynamic area. In this process, the signal variable unit 410 may generate additional information for notifying the neighboring node 100 that the data of the static region is included in the dynamic region. Accordingly, the signal variable unit 410 may include a signal component and an additional information generator.

The microprocessor 420 is responsible for the overall control in the node 100. In other words, in addition to controlling the determination unit 400 and the signal variable unit 410 as shown in FIG. 4, the interface unit 300 and the data transceiver 320 of FIG. 3 may also be controlled. .

The data transceiver 320 may include a transceiver for FlexRay and CAN communication, and may further include a transceiver for LIN communication. The data transmission / reception unit 320 transmits the variable data provided under the control of the control unit 310, more precisely, the microprocessor 420 constituting the control unit 310 to the neighboring nodes 100. In this case, the data transmitting and receiving unit 320 may transmit data using another transmitting and receiving unit when a failure occurs in a specific transmitting and receiving unit for the flex ray communication under the control of the control unit 310. This is represented by the notation J30 and J31 in FIG.

As a result of the above configuration, the embodiment of the present invention can guarantee the driver's safety by providing deterministic data not only in the static region but also in the dynamic region, and also redesigns the signal error and the FlexRay network. You can save additional costs.

5 is a diagram illustrating a method for controlling a flexlay network according to an embodiment of the present invention.

For convenience of description, referring to FIG. 5 together with FIGS. 1 and 2, the node 100, that is, the control device, may first determine the data size of the static area in the communication period of FIG. 2 (S501). In other words, when a driver in a vehicle makes a request such as braking, the deterministic data that should be transmitted to the neighboring node 100 to perform a specific function is allocated to a node 100 for performing a specific function. It will be judged if the standard is exceeded. Here, the static region represents a static segment, but since only the payload constituting the static segment may be represented, embodiments of the present invention will not be limited thereto.

If the determination result exceeds the allocated criterion (S503), the node 100 is configured to distribute the excess deterministic data to the dynamic domain to configure a signal, that is, the data (S505). Such a process is preferably performed in a corresponding cycle, and each node 100 may perform such a process every cycle. Furthermore, the node 100 may generate and insert additional information for informing the neighboring node 100 when the signal is distributed in the process.

Thereafter, any node 100 generating the signal transmits the signal to the surrounding node 100 (S507).

On the other hand, if it is determined in step S503 that the deterministic data does not exceed the size of the static region, the data is loaded only in the static region and transmitted to the peripheral node 100.

On the other hand, when a signal is received from the surrounding node 100, any node 100 can analyze the frame configured in the slot of the static segment to determine whether the signal is distributed to the dynamic segment, and according to the determination result You will be able to handle it.

While the invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

100: node 110: bus
300: interface unit 310: control unit
320: data transmission and reception unit 400: determination unit
410: signal variable unit 420: microprocessor

Claims (8)

A plurality of nodes; And
Including a bus (bus) for connecting the plurality of nodes to each other,
Each of the plurality of nodes,
Comprising a signal comprising a static area of the predetermined size and a dynamic area determined to be dynamic (dynamic), and comprises a control unit for controlling to transmit the configured signal to the peripheral node through the bus,
If the size of data to be recorded in the static area exceeds the size allocated to the static area, the control unit configures the signal by recording the excess data in the dynamic area,
And said static area processes deterministic data to ensure user safety. The method of claim 1,
The control unit,
Configure the signal divided into a plurality of time slots during one cycle time according to a FlexRay communication period, wherein the plurality of time slots comprise the static area, the dynamic area, a symbol window area, and a network idle time. divided into (network idle time),
And the plurality of nodes are synchronized with the control unit to receive and process the signal in a time slot corresponding to each node. A control device connected to a flexlay network,
A transmitter for transmitting a signal including a static area of a predetermined size and a dynamic area determined to be dynamic to each node connected to the FlexRay network; And
The signal is configured and provided to the transmission unit, and it is determined whether the size of data to be recorded in the static area exceeds the size allocated to the static area. Including a control unit,
And said static area processes deterministic data to ensure user safety. The method of claim 3,
The control unit,
And when the excess data is recorded in the dynamic area, an indicator for notifying whether the dynamic area is used or not is added to the static area. Determining whether the size of data to be recorded in the static area exceeds the size allocated to the static area;
If the size of the data exceeds the size allocated to the static region, distributing the data into the static region and the dynamic region to construct a signal; And
Transmitting the configured signal to a peripheral node,
And said static zone processes deterministic data to ensure user safety. The method of claim 5,
Comprising the signal,
And as much data as the size allocated to the static area is recorded in the static area, and excess data is recorded in the dynamic area to configure the signal. The method of claim 5,
And when the excess data is recorded in the dynamic area, an indicator for notifying whether the dynamic area is used or not is added to the static area. The method of claim 5,
Comprising the signal,
Configure the signal divided into a plurality of time slots during one cycle time according to the FlexRay communication period,
And the plurality of time slots are divided into the static region, the dynamic region, a symbol window region, and a network idle time.

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