CN104331292A - Method for generating configuration for middleware protocol conversion of Internet of vehicles - Google Patents

Abstract

The invention discloses a configuration generation method for the protocol conversion of the Internet of Vehicles middleware. The configuration of the method realizes the rapid development of the protocol conversion module. By reading the description information of the DBC file written according to the communication protocol of the Internet of Vehicles, the vehicle enterprise is added in the configuration tool. Communication protocol conversion parameters, the configuration information is stored in the database, and the protocol conversion module code of the Internet of Vehicles middleware is automatically generated by using the protocol conversion template file. Quickly integrate the body network with other networks to realize the communication of the Internet of Vehicles. The configuration tool of the invention can automatically generate configuration files and application program frameworks, and can check user configurations for errors, avoiding workers' intervention as much as possible, reducing error rates, thereby actively improving the stability of the protocol conversion module.

Description

A configuration generation method for Internet of Vehicles middleware protocol conversion

technical field

The invention belongs to the technical field of the Internet of Vehicles, and relates to a method for generating configurations of middleware protocol conversion of the Internet of Vehicles.

Background technique

The Internet of Vehicles is one of the key development targets of the Internet of Things in the future. We can realize some functions of handheld smart devices such as entertainment and phone calls through vehicle-mounted terminal equipment. At the same time, we can also remotely understand the working status of various components of the vehicle, the location of the vehicle, and the remote update of in-vehicle equipment programs in real time through the wireless network. Real-time statistics and analysis of vehicle location can also be realized through vehicle-to-vehicle communication and vehicle-to-road communication, providing real-time data for traffic dispatching and vehicle active safety systems. Therefore, the vehicle terminal application program not only contains some common functions, but also brings new application requirements. As an important part of the Internet of Vehicles, the vehicle-mounted intelligent terminal is a bridge connecting the vehicle with other networks, and needs to exchange information with the in-vehicle network and the off-vehicle network. At the same time, future vehicle-mounted terminals include not only fixed devices, but also handheld devices. With the development of Internet of Vehicles technology, after-installed terminals can be directly replaced by handheld terminals, such as mobile phones, tablet computers, etc., and these devices use different software platforms. At the same time, the important carrier of the Internet of Vehicles, the car, has differences in its vehicle network communication protocols due to different manufacturers. The current research and development of intelligent terminals for the Internet of Vehicles are basically customized on the basis of automobile manufacturers. The Internet of Vehicles terminals of different companies are not interchangeable. Interchange of IoV terminals and software sharing on the same platform are inevitable trends in the development of IOV.

With the application development of the Internet of Vehicles, in order to reduce development costs, the exchange of equipment and software is an inevitable trend. Since the vehicle networking application function of the vehicle terminal is not available in general embedded devices, it is necessary to connect the vehicle body network, vehicle dedicated short-range communication network DSRC (Dedicated Short Range Communications), 2G/3G and other networks to jointly transmit vehicle networking information. At the same time, the vehicle-mounted information terminal transmits the same information through the network of different standards connected to it, and the information is no different from that of the vehicle-mounted terminal.

In the Internet of Vehicles architecture, the terminal needs to communicate with the vehicle body network, in-vehicle network equipment, information terminals of nearby vehicles, roadside terminal equipment, and the Internet of Vehicles service center to achieve functions such as vehicle-vehicle/vehicle-road coordination. Various application services need to be provided to communicate with these networks. The transmission of these information is mainly through 3G mobile communication, short-distance dedicated radio communication (DSRC), bluetooth communication, WIFI communication, body bus, etc. to realize information interaction.

In order to solve the interaction of vehicle information in the Internet of Vehicles, these networks must be integrated to serve for vehicle information interaction. In these communication networks, different networks have different networking methods, different data formats and access methods, and different message formats designed by different vehicle companies, which belong to heterogeneous networks. Except for the body network, other communication networks are common. Effectively integrating these networks, unifying the information communication method and message format of the Internet of Vehicles, and providing a standardized access interface are the problems that need to be solved in the current application development of the Internet of Vehicles. In order to make full use of existing equipment and enhance the sharing of Internet of Vehicles application software, middleware technology is a technology with greater compatibility and portability without changing the usage habits of existing users and equipment.

In the middleware development process, the middleware message bus acts as a high-speed channel for information interaction of various components. The communication protocol between the components mounted on the message bus is a custom protocol suitable for the middleware of the Internet of Vehicles. In order to integrate the vehicle body information into the middleware message bus, it is necessary to obtain the vehicle body network information, and then it is necessary to realize the protocol conversion function between the vehicle CAN communication protocol and the vehicle networking middleware message bus. The vehicle CAN protocol is different for different car companies. It is the core technology of car manufacturers and is generally not disclosed.

The existing protocol is converted to middleware developers through manual coding on the basis of understanding the vehicle CAN protocol, that is, car companies need to disclose the body network protocol, which is not conducive to protecting the intellectual property rights of car companies, and the efficiency of manual coding is not high. Bad sex and other shortcomings. The existing development methods are not suitable for the development and application of middleware. Therefore, in order to realize the integration of vehicle networking information and protocol conversion, it is necessary to find a method that can not only protect the intellectual property rights of car companies, but also improve development efficiency and the versatility of protocol conversion modules.

Contents of the invention

In order to overcome the defects in the prior art, the present invention provides a configuration generation method for the conversion of the Internet of Vehicles middleware protocol, the configuration realizes the rapid development of the protocol conversion module, by reading the description information of the DBC file written according to the communication protocol of the Internet of Vehicles, Add the vehicle enterprise communication protocol conversion parameters in the configuration tool, that is, the protocol described in the DBC file is mapped to the unified custom protocol under the framework of the middleware NGTP (Next Generation Telematics Protocol) through the graphical interface configuration, and the configuration information is stored in the database. Using the protocol The conversion template file automatically generates the vehicle networking middleware protocol conversion module code with the assistance of the automatic code generation technology JET (JavaEmitter Templates). Quickly integrate the body network with other networks to realize the communication of the Internet of Vehicles. Its technical scheme is as follows:

A method for generating configurations of the Internet of Vehicles middleware protocol conversion, comprising the following steps:

(1) record communication protocol information with DBC file;

(2) Carry out conversion agreement parameter configuration through the configuration tool of graphical interface, and store information in the database file;

(3) The middleware communication protocol conversion code is automatically generated through the automatic code generation technology.

Preferably, for the analysis and database storage of the body application protocol description file DBC file.

Preferably, the configuration and storage of the communication protocol description are as follows: read the DBC file in the configuration tool, store the configuration information in the database file after configuration, and pass the configuration generation to the protocol conversion according to the format of the middleware standard protocol Protocol conversion mapping parameters for template files.

Preferably, the automatic code generation technology is used to finally generate the code for the protocol conversion, and without manual modification, the communication component is generated after compiling for the middleware communication of the Internet of Vehicles.

Compared with prior art, the beneficial effect of the present invention:

1) Lower the threshold for development;

Users do not need to spend energy to familiarize themselves with the middleware and the middleware message bus protocol, but only need to import and configure the one-to-one mapping relationship between the protocols in the newly created project.

2) Protect the intellectual property rights of car companies;

Middleware is used for communication between body networks, and it is the core part of shielding different body networks. This module realizes the conversion between the body communication protocol and the standard communication message format, and provides normal communication between the application and the body network. This part is automatically generated by the car company through the configuration tool configuration according to the middleware protocol standard to automatically generate the target code to protect the intellectual property rights of the car company.

3) Improve stability;

The configuration tool can automatically generate configuration files and application frameworks, and check the user's configuration for errors, avoiding workers' intervention as much as possible, reducing the error rate, and thus actively improving the stability of the protocol conversion module.

4) The portability and versatility of the generated code between different platforms;

On the one hand, the protocol conversion module and the underlying driver module adopt a unified function interface, and only need to replace different driver interfaces for unused underlying CAN interface platforms; on the other hand, the protocol conversion template code is described in C language, which is applicable to UNIX-like platforms and Android platform.

Description of drawings

Fig. 1 protocol conversion implementation flow chart;

Fig. 2 protocol conversion model diagram;

Figure 3 protocol conversion map;

Figure 4 configuration tool block diagram;

Figure 5 protocol configuration flow chart;

Figure 6 protocol conversion template file flow chart;

Figure 7 Protocol conversion template UML sequence diagram;

The code in Figure 8 automatically generates a diagram;

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

The structure of the protocol conversion implementation flow chart is shown in Figure 1. The car company inputs the protocol through the analysis of the DBC file to form a variable database. The use of the database is to facilitate the conditional search and secondary import of protocol information. The data item contains the information describing the input, including CAN ID, start bit, end bit, offset, scale factor and a series of information that accurately describe the protocol variables. The message bus protocol file is a file describing the message bus communication protocol of the IoV middleware.

The processing method module analyzes the information obtained from the configuration, including variable matching, shifting, and search operations, obtains the input parameters of the code template, and passes it to the code template file.

The code template file automatically generates the protocol conversion code with the assistance of the configuration tool through the input information and the detailed rules of the background protocol. After compilation, the communication component of the protocol conversion is generated to replace the middleware component of the protocol conversion of different models. The backup database and backup DBC file store the configured protocol information description, which is convenient for importing the configuration for similar protocol conversion after minor adjustments.

Protocol conversion input includes: DBC file import, configuration interface input, database file, protocol conversion template file. The output of protocol conversion includes protocol conversion code and database files.

According to the above, the functional realization of the present invention includes the following four aspects:

1) File parsing and storage; use the file operation functions and regular expressions in Eclipse to match the file content, and parse the CAN application protocol DBC general description file, such as matching "SG_FarLightOpen:2|21+(1,0)[0|0 ]""Gateway" in the string name of SG_FarLightOpen obtains the high beam control information in the vehicle CAN protocol information and stores it in the database; the analysis and storage of the protocol description file is to prepare for the next configuration conversion.

2) Protocol conversion configuration mapping; generate protocol conversion template parameters and provide them to the protocol conversion template. Taking the Internet of Vehicles middleware message bus protocol as the standard, the relationship between the two protocols is mapped one by one according to the information required by the Internet of Vehicles. As shown in Table 1, the body CAN protocol data frame contains ID and DATA information, and the middleware protocol contains function Code, function subcode and data field information are mapped to achieve the purpose of parsing protocol message headers, specific bits in the data field, and variables.

Table 1 Protocol Mapping

Body CAN Protocol Use Cases Mapping relations Middleware Protocol Use Cases ID+DATA <————> Function code + function subcode + data field

The mapping relationship is completed by the car companies themselves by relying on configuration tools through "information name" matching, thus protecting the intellectual property rights of car companies.

3) Protocol conversion template design; reduce complexity and improve reliability. The protocol conversion template includes all information that the protocol conversion module has nothing to do with the specific protocol, including data collection, control classification processing, and also includes the operation of the CAN interface, and the implementation code for the receiving and sending operations of the middleware message bus interface; The creation code of the sending and receiving threads does not need to be changed for different modules. The code that needs to be changed is implemented in the template in the form of variable parameters. For example, the control code for turning on the high beam is different for different configurations, so its value code is expressed in the following form, FFMask_State_FarLight_open1=0x<%=elementList. get(0).toString() %>. The right-hand side of the variable is variable assignment, which is finally assigned using automatic code generation.

4) Automatic code generation; the final protocol conversion needs to be completed by code implementation. The above relationship is realized by combining the configuration tool with the code template, and the JET code generation method is used to automatically generate the middleware protocol conversion module code. JET uses the replacement variable string The code for the method implementation is automatically generated.

To realize protocol conversion, it is necessary to establish a protocol conversion model (Figure 2). Due to the characteristics of car enterprise agreement intellectual property protection and other characteristics, the protocol conversion module of the Internet of Vehicles middleware needs to be implemented in the form of configuration, specifically the mapping relationship between configuration protocols (Figure 2). 3), the final protocol conversion is obtained by implementing the specific configuration process (Figure 5) by means of the configuration tool (Figure 4), and the final automatic generation of the protocol code (Figure 8) requires the code conversion template file (Figure 6) to obtain the parameters generated by the configuration . The processing sequence of the code template information is shown by the protocol conversion template UML sequence diagram (Figure 7).

1) File parsing and storage

The analysis of the protocol description file analyzes the format composition of the two different protocols to be converted in detail, and provides the basis for the conversion and mapping relationship of the protocols.

See Figure 1, where file parsing and storage

Analyze the DBC general description file of the CAN application protocol to obtain the CAN protocol information of the vehicle, such as matching the DBC file information of "SG_FarLightOpen:2|21+(1,0)[0|0]""Gateway", obtain the following table 2 information that fully describes each data segment displayed. Each data segment accurately describes the CAN protocol information of a node.

Table 2 Body CAN Protocol Use Cases

node name ID start bit occupied bit scaling factor endian the smallest maximum unit/value high beam on 7A0 2 2 1 - - - 0x11 left front tire pressure 7A8 0 4 0.1 the s 0 5 bar

Analyze the Internet of Vehicles middleware message bus protocol, as shown in Table 3, the transmission of control commands mainly includes control function codes, function subcodes and data fields. The data field of the analog quantity is processed according to the agreed processing method (integer, single-precision floating point, double-precision floating point).

Table 3 Middleware Protocol Use Cases

information name protocol function code function subcode protocol data field high beam on 4001 0001 17 left front tire pressure 4002 0005 Data

2) Conversion configuration mapping based on NGTP protocol

The configuration mapping of the protocol conversion is the core part of the protocol conversion; the model of the protocol conversion is established first, and the mapping relationship and realization of the specific fields of the protocol conversion are detailed on the basis of the model. Then briefly describe the implementation tools of the specific mapping relationship, the simple structure of the configuration tool and the flow chart of the enterprise to realize the configuration mapping.

See Figure 2, protocol conversion model diagram

The on-board information terminals of different cars can read the information of the body control module BCM through the CAN interface, and the read BCM information is converted into the middleware communication protocol format by the message conversion module, and the converted information is sent to the middleware message bus, and finally To the Internet of Vehicles application (mainly including mobile terminal applications, remote service terminals of car companies, and Internet of Vehicles applications of other service terminals), the Internet of Vehicles application can also send messages to the vehicle information terminal, and send them after conversion through the middleware protocol conversion module to the body control module. The key to the communication between the background service and the body is the mutual conversion of different protocols by the protocol conversion module.

As a part of the middleware of the Internet of Vehicles, the protocol conversion module has one end of the interface as the body CAN bus and the other end as the middleware message bus. The CAN communication bus network is connected to the specific vehicle network through the CAN transceiver; the middleware message bus is a virtual bus on which various communication components and application components of the middleware are connected, and each component is carried out through this virtual message bus. communication. Among them, the description of the CAN communication protocol adopts the CAN application protocol standard description method of Vector Company DBC file description method; the DBC file contains nodes, variable start bits, stop bits, ranges, offsets, etc., which are sufficient to describe and analyze the overall information of a CAN network . Both MATLAB and the mainstream CAN bus protocol analysis and testing software CANoe support files in this format. The middleware communication protocol adopts a custom protocol under the framework of the next-generation Internet of Vehicles protocol NGTP (NextGeneration Telematics Protocol).

See Figure 3, the protocol conversion map;

Transformation mapping mainly includes transformations in two directions, that is, sending and receiving processes. In the sending process, the middleware protocol distinguishes the messages sent to different components through the analysis of function codes and function subcodes. The combination of function code 4001 and function subcode 1001 in the right column in Table 4 below indicates the message sent to the body; The combination of code 4001 and function subcode 2001 indicates a message to the engine. Then according to the information in the data field, determine the specific components sent to the car sound, that is, determine the specific set and reset positions in the frame in the sent CAN message. The data field 17 in Table 4 indicates that the high beam control is turned on, the ID is 7A0 mapped to the CAN protocol of the vehicle body, and the 0-1 in the first section of the 8 bytes of the data frame is set to 1. The receiving process is the opposite process of the sending process, and the value of the function code and data field is determined according to the body CAN protocol ID and the analysis of the bit status in the 8 bytes of the data frame.

Table 4 Protocol Mapping Use Case (High Beam)

Body CAN Protocol Use Cases Mapping relations Middleware Protocol Use Cases ID(7A0)+DATA(0x11) <————> Function code (4001) + function subcode (1001) + data field (17)

See Figure 4 Configuration Tool Structure Diagram

The configuration tool itself is a Windows application program, which includes a file parsing module, a view module, a code generation module and a database operation module. The file parsing module parses the DBC file; the view module includes functions such as view, browsing, and editing required for configuration; the code generation module is based on the JET code generation method; the database operation module uses the database operation class provided by Eclipse to write SQL standard scripts Languages operate on data.

See Figure 5 for protocol configuration flowchart

The car company completes the configuration of the protocol according to the protocol configuration flow chart, creates or imports an existing configuration information after starting the configuration tool, configures the protocol information on the configuration tool according to the CAN protocol description of the target model and selects the corresponding protocol conversion code template document. The configured parameters include the corresponding relationship between the middleware protocol and the body CAN protocol, and the corresponding relationship is matched by the variable name. As shown in Table 5 below, the configuration is performed with the variable names specified in the middleware protocol as standard. In the corresponding CAN protocol of the vehicle body for which different middleware standard protocols are selected, the protocol of the vehicle body is configured according to the specified table items.

Table 5 Detailed list of configuration items

After completion, check the correctness of the configuration, including whether the CAN label information is correct, whether the CAN data information is repeated, and whether the template is correct. After checking, click the automatic code generation of the configuration tool, and the generated code will be compiled in the target compilation environment to generate a protocol conversion module. Install the protocol conversion module on the vehicle information terminal to realize the conversion of the Internet of Vehicles protocol and realize the two-way interaction of communication. Among them, the CAN transceiver function adopts the SocketCAN standard interface.

3) Protocol conversion template design

The protocol conversion template file is the master version of the final code, including all the code implementation of the protocol conversion, specifically including the code framework file of the protocol conversion. The correctness and reliability of the final code are guaranteed.

See Figure 6 for the protocol conversion template file flow chart and Figure 7 for the protocol conversion template UML sequence diagram

The main function of the template is to obtain the specified message from the CAN network, extract the useful part and encapsulate it into the middleware standard format and send it to the middleware message bus, and in the opposite process, convert the control command sent by the message bus into a CAN message for format conversion . Among them, converting data is carried out in the process of sending and receiving. For the application program, receiving data is a query process, and sending data is a control process.

Extract the protocol-related information in the code as the parameters of the template. The parameters of the template are calculated from the configuration information of the configuration tool. The flow chart of the protocol conversion template program is shown in the figure. The main function is the entry point of the entire template program. The protocol conversion template program mainly includes the sending and receiving of messages, that is, the send_threadfun sending thread and the receive_threadfun receiving thread. The main tasks focus on the message receiving process , receiving thread processing refers to receiving and processing messages sent by the message bus, including control messages, query messages and emergency messages, corresponding to the control process, query process and emergency process shown in the figure. The template file is written in C language, and finally compiled into a dynamic link library to ensure the versatility and replaceability between the Linux system and the Android system.

In the calculation process of the control flow, because the state of the vehicle body needs to be obtained to fill the state of the non-control bit in this message, the process of the query flow is included. For example, the first two digits in the binary bit 0101 represent the window control bit, and the last two digits represent the high beam control bit. When the high beam control operation is performed, the first two window control bits are the non-control bits of this CAN control message. The bit needs to keep the original state, so before the CAN control message is sent to the bus, it is necessary to query the original window control bit state. Refer to the UML sequence diagram of the protocol conversion template in Figure 7. The calculation flow of a typical control message is as follows:

(1) The middleware message bus sends control commands to the communication component, and the main function of the communication component is protocol conversion.

(2) Parse, split the message according to the definition of the background message, judge the control bit that needs to be controlled, such as the high beam is turned on, and obtain the controlled mask according to the control mask obtained from the configuration, such as the high beam_on control code 0x0000000000000001 (standard data frame 64 bits).

(3) CAN query message is sent, and the status of other control bits in the current control bit-related message is queried once, and the status code 0x0000000000000010 is returned by the CAN query message.

(4) The status code is ORed with the control mask

HIGH BEAM_ON CONTROL MASK || STATUS CODE GET SENT DATA FIELD 0x0000000000000011.

(5) Encapsulate the data field and CANID into a CAN data frame and send it to the bus through the CAN interface.

The fragmentation and reassembly operations in the Internet are due to the different MTU values of different communication networks, and the fragmentation and reassembly operations in the figure are because the information required by the data field of the middleware message bus protocol corresponds to different CAN network nodes, so It is necessary to request data separately, and then query the combination after receiving and analyzing the returned data.

4) Automatic code generation

Automatic generation of source code can save users from knowing the specific code details of middleware code, make it easier to generate qualified code, save us time, reduce complexity, and shorten the development cycle.

See Figure 8 code automatic generation diagram

While machine-automated source code generation is powerful, inserting code into a program becomes complex and difficult to understand. One way to reduce complexity and increase readability is to use templates.

In the Eclipse Modeling Framework (EMF) project, there are two very powerful tools for generating source code: JET (JavaEmitter Templates) and JMerge (Java Merge). Use the JET code generation method in eclipse to generate code in the form of string parameters. Since the generated code needs to provide a communication interface for the message bus, and the communication protocol is not standardized, the template-based code generation method is adopted to ensure the code readability.

As shown in the figure, the process of automatic code generation is to define a template, generate a java intermediate class through the JET engine, and the intermediate class has a generate method, and finally generate a string code according to the configuration parameters. From the user's point of view, usually do not know the existence of the JET engine and the intermediate class, only need to edit the template code, pass in the configuration parameters, and use the intermediate class method to generate the code file.

As shown in the simple template example below, for the switch control of low beam and high beam, the parameter passed in by the code is argument, which is a list array, and the array contains all passed parameters.

The final generated code based on the above is:

The hexadecimal field contains the configured CAN application protocol information. For example, when the high beam is turned on, the value of the variable FFMask_State_NearLight_open1 is sent, the lowest 2 bytes are 0xC1, and the other high bytes are filled according to the query state.

During the code generation process, the configuration parameters in the figure are the basis for the final code generation. The parameters passed by the code generation mainly include:

Digital quantity: The parameter includes the all-1 mask of this digital quantity in the CAN message information and the control (status) mask of each variable. These masks are all obtained from user-configured parameters through conditional query, shift, and or calculation operations.

Analog quantity: The parameter includes the mask of all 1s of this analog quantity in the CAN message information and the method of processing this original analog quantity. Such as integer, single precision floating point or double precision floating point processing.

Others: CAN communication interface function, when the protocol conversion module reads CAN bus information of different platforms, different CAN reading interfaces may be used.

The final generated code file is a combination of c file and h file, and the target file is automatically generated with the assistance of compiling link file and make tool.

The above is only the best implementation mode of the present invention, any simple changes or equivalent replacements of the technical solutions that can be clearly obtained by any person skilled in the art within the technical scope disclosed in the present invention all fall into the scope of the present invention within the scope of protection.

Claims (4)

1. A configuration generating method for Internet of Vehicles middleware protocol conversion, characterized in that, comprising the following steps: (1) record communication protocol information with DBC file; (2) Carry out conversion agreement parameter configuration through the configuration tool of graphical interface, and store information in the database file; (3) The middleware communication protocol conversion code is automatically generated through the automatic code generation technology. 2. The configuration generation method of the Internet of Vehicles middleware protocol conversion according to claim 1, characterized in that, for the analysis and database storage of the vehicle body application protocol description file DBC file. 3. The configuration generating method of the Internet of Vehicles middleware protocol conversion according to claim 1, wherein the communication protocol description configuration and storage are specifically: reading the DBC file in the configuration tool, and storing the configuration information after configuration In the database file, according to the format of the middleware standard protocol as the standard, configure and generate the protocol conversion mapping parameters passed to the protocol conversion template file. 4. The configuration generation method of the Internet of Vehicles middleware protocol conversion according to claim 1, characterized in that, using automatic code generation technology, the code for protocol conversion is finally generated, and the communication is generated after compilation without manual modification. Component, used for communication between the middleware of the Internet of Vehicles.