CN103200707B - A kind of middleware of the meteorological data observation system based on wireless sensor network - Google Patents

Abstract

The invention discloses a kind of middleware framework being applied to meteorological data observation system, as the bridge connecting wireless sensor network and the Internet, the contact transmission of data can be carried out fast, flexible operation, wide accommodation between sensor network end and meteorological data observation center.Meteorological data observation system middleware based on wireless sensor network provided by the invention, comprise the CWSN subsystem be connected with meteorological wireless sensor network and the CPC subsystem be connected with meteorological data observation center,? AD is passed through between CWSN subsystem and CPC subsystem? HOC network communicates; Described CPC subsystem comprises CPC network connecting module, network self-adapting module, CPC auto-update module and command process module, and described CWSN subsystem comprises serial communication modular, CWSN network connecting module, WSN packet handing module, XML file processing module and CWSN auto-update module.

Description

Middleware of meteorological data observation system based on wireless sensor network

Technical Field

The invention belongs to the technical field of wireless sensor network middleware, and particularly relates to middleware of a meteorological data observation system based on a wireless sensor network.

Background

At present, meteorological data observation systems are divided into wired and wireless modes according to data transmission modes. The wired transmission mode can well realize the acquisition of meteorological data, but has the defects of high line cost, difficult pavement in mountainous areas, complex maintenance and the like. The wireless transmission mode can provide high service quality and high-efficiency bandwidth utilization while saving cost, so that the wireless transmission mode is mostly adopted for data acquisition at present.

Meteorological data observation systems typically include a wireless sensor network, which is a wireless network of a large number of stationary or mobile sensors that cooperatively sense, collect, process and transmit information about objects sensed within a geographic area covered by the network (e.g., temperature, sound, vibration, pressure, motion or pollutants, etc.) and ultimately transmit such information to the network owner. Wireless sensor networks are the third wave of the world information industry following computers and the internet, and have become the strategic focus of a new round of global economic and technological development. With the continuous and deep research, the wireless sensor network can gradually be integrated into various fields of daily life and social activities of people. If the internet forms a logical information world and changes the communication mode between people, the wireless sensor network fuses the logical information world and the objective physical world together and changes the interaction mode between people and nature. A person can acquire a large amount of information of an objective world through the wireless sensor network at any time, any place and even any environmental condition, and the functions of the network and the capability of the human to know the world are greatly expanded.

A wireless sensor network generally includes a sensor node (sensorode), a sink node (sinnode). After the wireless sensor network is formed, various sensor nodes collect data, but due to the limited resources, the various sensor nodes cannot have enough network communication capacity, and the collected data is less likely to be transmitted to a remote data monitoring center. But still have a lot of problems such as high power consumption, data acquisition are inconvenient, maneuverability is poor, intelligent level is low, data communication is unstable.

Disclosure of Invention

In order to solve the problems, the invention discloses a middleware framework applied to a meteorological data observation system, which is used as a bridge for connecting a wireless sensor network and the Internet, can quickly transmit data to and from a sensor network end and a meteorological data observation center, and has the advantages of flexible operation and wide application range.

In order to achieve the purpose, the invention provides the following technical scheme:

the middleware of the meteorological data observation system based on the wireless sensor network comprises a CWSN subsystem connected with the meteorological wireless sensor network and a CPC subsystem connected with a meteorological data observation center, wherein the CWSN subsystem and the CPC subsystem are communicated through an ADHOC network;

the CPC subsystem comprises a CPC network connection module, a network self-adaption module, a CPC automatic upgrading module and an instruction processing module,

wherein,

the CPC network connection module is connected with the CWSN subsystem through an ADHOC network, is connected with the meteorological data observation center through the Internet, receives data sent by the CWSN subsystem, forwards the data to the server side, receives data sent by the server and sends the data to the CWSN subsystem;

the network self-adaptive module is started when the CPC subsystem is connected with the internet for the first time, and the mode of accessing the network is adjusted according to the current connection state of the CPC subsystem and the network;

the instruction processing module is used for judging and processing an instruction sent by the meteorological data observation center;

the CPC automatic upgrading module acquires an executable file of a meteorological data observation center, which can be directly operated on an embedded platform, updates the existing operating program or adds an operating program which is not available on the embedded platform;

the CWSN subsystem comprises a serial port communication module, a CWSN network connection module, a WSN packet processing module, an XML file processing module and a CWSN automatic upgrading module:

wherein,

the serial port communication module is used for receiving data sent by the wireless sensor network, transmitting the data to the WSN packet processing module for processing, receiving an instruction from the CPC subsystem and transmitting the instruction to the wireless sensor network;

the WSN packet processing module is used for analyzing the WSN data packet received from the serial port communication module, transmitting the analyzed data to the XML file processing module, packaging the data transmitted from the XML file processing module into the WSN data packet and transmitting the WSN data packet to the serial port communication module;

the XML file processing module is used for analyzing the XML file sent from the CPC system, transmitting the XML file to the WSN packet processing module, generating the XML file from the data transmitted from the WSN packet processing module, and sending the XML file to the CWSN network connection module;

the CWSN network connection module is used for connecting the CPC subsystem and carrying out data communication with the CPC subsystem;

the CWSN automatic upgrading module acquires an executable file of the meteorological data observation center, which can be directly operated on the embedded platform, through the CPC subsystem, and updates the existing operating program or adds an operating program which is not available on the embedded platform.

As a preferred scheme of the present invention, the network adaptation module automatically selects a smooth network for connection according to the order of the ethernet, the wireless local area network, and the 3G network.

Compared with the prior art, the invention has the following advantages and technical effects:

1. the middleware is used as a sensor network end and a meteorological data observation center, has the characteristics of high efficiency, real-time response, high reliability, low power consumption, strong anti-interference capability and the like, and has good universality.

2. The CWSN subsystem and the CPC subsystem in the middleware form an ad hoc network, all nodes in the network are equal in position, a central node is not required to be arranged, and therefore when two nodes cannot directly communicate, data exchange can be achieved through forwarding of a plurality of intermediate nodes, and the ad hoc network has strong survivability.

3. Each system in the middleware can move rapidly as required to realize the dynamic change of the network topology to meet the requirements of different occasions.

4. The CPC system and the CWSN system can realize automatic updating of programs, and a way is provided for automatic upgrading of middleware deployed in an unmanned monitoring area.

5. The middleware can select the physical link according to the existence of the physical link, and finally selects the most practical channel, so that the middleware has strong self-adaptability.

6. The middleware is developed and operated on the embedded platform, and has high integration due to the characteristics of the embedded equipment.

Drawings

FIG. 1 is a schematic diagram of a middleware structure provided by the present invention;

FIG. 2 is a schematic diagram of a working flow of a CPC network connection module;

FIG. 3 is a schematic diagram of information interaction between a CPC automatic upgrade module and a data observation center;

FIG. 4 is a schematic diagram of a workflow of a CPC automatic upgrade module;

fig. 5 is a schematic diagram of information interaction between the CWSN automatic upgrade module and the data observation center;

Detailed Description

The technical solutions provided by the present invention will be described in detail below with reference to specific examples, and it should be understood that the following specific embodiments are only illustrative of the present invention and are not intended to limit the scope of the present invention.

The invention is developed and operated on an embedded platform, the invention uses an ARM11 development board based on an S3C6410 kernel, but other embedded devices can be developed and operated. The structural principle of the middleware of the meteorological data observation system based on the wireless sensor network is shown in fig. 1, and the middleware comprises a CWSN subsystem connected with the meteorological wireless sensor network and a CPC subsystem connected with a meteorological data observation center server, wherein the CWSN subsystem and the CPC subsystem are communicated through an ADHOC network. The middleware provided by the invention plays a role of a bridge between the meteorological wireless sensor network and the meteorological data observation center server, and realizes information interaction between the meteorological wireless sensor network and the meteorological data observation center server. The CWSN subsystem and the CPC subsystem are in a many-to-one relationship, a large number of CWSN systems send connection requests to the CPC subsystem, the CPC subsystem responds to the clients one by one through judgment, and the function of forwarding the client data to a data observation center can be realized. Instead, the observation center can also send messages to the CWSN system by the same principle.

The CPC subsystem comprises a CPC network connection module, a network self-adaption module, a CPC automatic upgrading module and an instruction processing module:

the CPC network connection module is connected with the CWSN subsystem through an ADHOC network, and is connected with the meteorological data observation center platform through the Internet.

Specifically, the CPC network connection module includes three threads, a main thread, a client-side transceiving thread, and a PC server connection thread, and further creates a buffer 1 for storing data uploaded by the client and a buffer 2 for storing data transmitted from the server, and a flowchart thereof is shown in fig. 2. The workflow of these three threads is explained in detail below:

and (4) a main thread. The main thread is mainly responsible for connecting with the CWSN subsystem and creating two sub-threads. When the program runs, firstly, acquiring the address of a server for logging in a remote service application layer, if the address is not acquired, printing an error message by the program and quitting the program; if the correct address is obtained, a thread for connecting a remote server is created, and then a thread for receiving and sending client data is created. Establishing a local server through socket, bind, listen, and accept functions and continuously monitoring connection requests of the CWSN subsystem, once a client request exists, sending a byte random code by a main thread, then verifying a verification code sent by the client, if verification is successful, storing a socket of the corresponding client into a socket array, and if verification is unsuccessful, disconnecting and returning to a part for monitoring the connection of the CWSN subsystem.

And receiving and transmitting the client thread. When the CPC subsystem receives data uploaded by a client (namely, the CWSN subsystem), the CPC enters a thread part of a receiving and sending client, judges whether data exists in the data cache region 1, waits for processing of the data in the data cache region if the data exists in the data cache region 1, and stores the data in the data cache region 1 if the data does not exist in the data cache region. And judging whether the data cache region 2 has data or not, if not, returning to judge whether the cache region 1 has a data part or not, if so, judging whether the content in the data is directed to a CPC subsystem or not, if not, sending the data to each CWSN subsystem, finally emptying the data cache region 2, and returning to the thread starting part of the receiving and sending client. If the data is for the CPC subsystem, the data in the cache area 2 is sent to the instruction processing module, and the instruction processing module performs corresponding processing.

And connecting the PC server thread. On the contrary, when receiving data of the service application layer (i.e. the data observation center), the CPC determines whether there is data in the data buffer 2, and waits if there is data, and stores the data in the data buffer 2 if there is no data. And then judging whether the data exists in the data cache region 1, if so, calling a send () function, sending the data to a remote server, then emptying the content in the data cache region 1, returning to judge whether the data exists in the data cache region 2, otherwise, directly returning to judge the data cache region 2.

The network self-adaptive module is started when the CPC subsystem is connected with the internet for the first time, and the module adjusts the mode of accessing the network according to the current connection state of the CPC subsystem and the network. In the case of complete network infrastructure, we can choose any one of ethernet, wireless lan, 3G network. Ethernet is more stable than both networks, but not all areas have ethernet interfaces, such as mountainous areas, islands, or areas with low smoke. When the infrastructure is not sound, the wireless local area network can be selected, and as long as the wireless router connected with the observation center is provided, the wifi module of the CPC subsystem can be connected with the service application layer. If the above two situations can not be met, only the 3G network is selected, and although the stability and the cost performance of the network are not better than those of the above two types, the network is convenient to connect and wide in coverage, and can completely meet the requirements of the system. The network self-adaptation unit starts the Ethernet card at first in the implementation process, through the ping command of ICMP agreement, if can return a fixed value when the physical link between Ethernet card and the router exists, through comparison return value and fixed value, then can judge whether the link of CPC system and remote center information show control platform is unobstructed, if unobstructed this unit withdraws from, if unobstructed, then set up wifi network card parameter, start wifi network card. And then, the ICMP protocol is used again for testing the network, if the network is successfully logged out, and if the network is not successfully logged out, the 3G network card starting program is operated. The 3G network card starting program is an executable dialing program written by a shell script language. In order to better realize the dialing function of the USB3G, a service program is run in the background, and the service program is set to run automatically when the computer is started, so when a 3G network card starting program is executed, an instruction is automatically sent through the background service program to carry out 3G dialing.

The instruction processing module is used for judging and processing instructions sent by the meteorological data observation center, such as: and if the instruction processing module analyzes the instruction for upgrading the program of the CPC subsystem, the CPC system immediately executes the CPC automatic upgrading module and waits for receiving the configuration file sent by the meteorological data observation center platform.

CPC automatic upgrade module. Since the CPC subsystem is a server side with respect to the CWSN subsystem, and the CPC subsystem is a client side with respect to the data observation center, the program update and upgrade of the CPC subsystem mainly involves two aspects, i.e. a first server side program and a second CPC client side program. Information interaction between the CPC automatic upgrading module and the data observation center during upgrading is shown in fig. 3, the configuration of an ftp server is mainly used for the server, the data observation center platform sends a client program updating instruction to the CPC subsystem, the CPC subsystem confirms after obtaining the client instruction, the data observation center platform sends ftp login and updating program information to the CPC subsystem after receiving confirmation information, the CPC subsystem performs corresponding operation according to the received configuration information, and if the requirements of a downloading program are met, the downloading program is started. After downloading the program, the downloaded program will be determined, and the working flow is shown in fig. 4. After the program download is received, analyzing the downloaded xml file again, extracting file size information, namely the size of the file _ size node, calculating the size of the downloaded updating program and recording the size as curr _ size, and comparing the file _ size and the curr _ size, wherein if the size values are not equal, the program is downloaded again if errors occur in the program download process; if the values are equal, the program downloading is successful. If the program is downloaded successfully, the running program is closed, the old program name is modified, and then the new program just downloaded is directly started: if the new program can be successfully operated, deleting the old version of program and the program configuration file in the xml format which is just downloaded; if the new program cannot be successfully run, the old version of the program is restarted.

The CWSN subsystem comprises a serial port communication module and a CWSN network connection module, wherein the serial port communication module is communicated with the wireless sensor network, and the CWSN network connection module is connected with the CPC subsystem. Because the file in the XML format has its own advantages, we choose to transmit data between the CWSN subsystem and the CPC subsystem through the file in the XML format, and the data sent from the wireless sensor network is a WSN packet, so the CWSN subsystem further includes a WSN packet processing module and an XML file processing module for data parsing and encapsulation.

The serial port communication module is mainly responsible for the communication problem between the wireless sensor network and the middleware, when the meteorological sensor in the wireless sensor network collects data, the data can be regularly sent to the only convergent node in the network, and then the convergent node sends the meteorological data which is just received to the CWSN system. The module is used for receiving data sent by a sink node in the wireless sensor network, transmitting the data to the WSN packet processing module for processing, and transmitting an instruction received from the CPC subsystem to the wireless sensor network. Specifically, the serial program communication unit is responsible for acquiring information from a sink node in the wireless sensor network, and mainly comprises the working state of the sensor node, acquired environmental parameters and the execution condition of a remote server command. The ttySAC1 serial port file is opened through an open () function, next operation is executed according to the condition whether the ttySAC1 serial port file is correctly opened or not, if the ttySAC1 serial port file is not opened successfully, the program can always execute the open () function, if the ttySAC1 serial port file is opened successfully, parameters of the serial port are set, and the parameters mainly comprise a baud rate, a data bit, a stop bit and a check bit.

And the CWSN network connection module is used for connecting the CWSN system and the CPC system through an aodv routing protocol by utilizing an Adhoc network and realizing information exchange between the CWSN and the CPC system through network programming.

The WSN packet processing module is used for analyzing and packaging the WSN data packet; the module analyzes a WSN data packet received from the serial port communication module and transmits the analyzed data to the XML file processing module, the data transmitted from the XML file processing module is packaged into the WSN data packet, and corresponding information of an ARMNode is added to the packet during packaging, wherein the ARMNode is a unique marker (which can be called CWSN address) for identifying hardware equipment where each CWSN subsystem is located, and the idea of identifying each computer by using an IP address is the same. The wireless sensor network needs to establish a reasonable data packet format, namely a WSN packet, for exchanging data with the CWSN subsystem. Table 1 below is an illustration of the packet format:

TABLE 1

All communication data between the CWSN subsystem and the wireless sensor network must begin and end with the fixed character "0 x 1A". Length indicates the size of this packet. The next byte is the unique identification number of the sensor node. Type is used to indicate the Type of sensor node. Data is the portion of Data collected by the sensor. Our sensor node is a module with multiple sensors. For example, temperature, moderate pressure sensors are integrated into a sensor node, and the sensors share a radio frequency module. Two bytes of the data part represent a data value, and at present, 3 sensors can be supported by our sensor node, so that the size of the data is made to be 6 bytes. Workingstate indicates the operating state of the sensor node, remaining power indicates the remaining power, and the use is described in the case of whether or not the power is on the warning. The acquistioncycle is a data transmission cycle of the radio frequency module. The WSN packet processing module analysis process comprises the following steps: the first and last bytes of the obtained WSN packet are first read to determine if they are 0x1A, and if one of them is not, the packet is discarded. If the head byte and the tail byte of the WSN data packet meet the requirements, reading the second byte and the third byte to judge whether the size of the second byte and the third byte is equal to the total byte size of the data packet, if the sizes of the second byte and the third byte are not equal to each other, indicating that the data packet is damaged, discarding the data packet; if the data are equal, the type of the data is identified according to the content of the next byte, and the data of the remaining bytes are respectively stored into corresponding database tables. In contrast to the WSN packet parsing process, when the CWSN subsystem sends a command to a sensor in the wireless sensor network, the format of the sent command packet must be recognized by the sensor node, otherwise the command packet is treated as an invalid packet by the sensor node, so the encapsulation process is to add necessary format characters on the basis of the data to be sent to make the data conform to the WSN packet format.

The XML file processing module is used for analyzing and generating an XML file; the module analyzes the XML file sent from the CPC system and transmits the XML file to the WSN package processing module, the data transmitted from the WSN package processing module generates a file in an XML format, and the process of analyzing and generating the XML file is similar to the process of processing the WSN package, and is not repeated herein. In the system, the xml files are classified according to types and mainly comprise files for transmitting sensor data regularly and response files for responding to commands of a remote data center. The file generation ideas of the two xml formats are the same, and the two xml formats are extracted from a database or corresponding data are obtained from a WSN file processing module, files in the xml formats are established through libxml2 library functions, and finally the files are transmitted in a data packet conversion mode. The XML file processing module also comprises a function of instruction processing similar to the instruction processing module in the CPC subsystem, namely, the XML file processing module is used for judging and processing the instruction sent by the meteorological data observation center through the CPC subsystem, if the instruction processing module analyzes that the instruction is the instruction for carrying out program upgrading on the CWSN subsystem, the CWSN subsystem can immediately execute the CWSN automatic upgrading module and wait for receiving the configuration file sent by the meteorological data observation center platform.

The CWSN automatic upgrading module sends a program upgrading instruction to the CWSN subsystem when the data observation center has a new version of a CWSN program, the CWSN system receives the program upgrading instruction and sends a response message to the data observation center, the response message shows that the configuration file of the program can be received at present, the data observation center receives the response message from the CWSN system, and if the configuration file is confirmed to be received, the data observation center sends the configuration file with the xml format to the CWSN, and the format of the configuration file is the same as the xml format in the CPC system program upgrading. The CPC automatic upgrade module performs information interaction between the CPC subsystem and the data observation center when upgrading as shown in fig. 5, after receiving the configuration file of the program update program, the CWSN main program determines whether the CWSN main program needs to be upgraded by judgment, and if upgrading, the CWSN main program sends information for determining a download program to the data observation center, so as to finally complete the function of program download.

The technical means disclosed in the invention scheme are not limited to the technical means disclosed in the above embodiments, but also include the technical scheme formed by any combination of the above technical features.

Claims (2)

1. A middleware of a meteorological data observation system based on a wireless sensor network is characterized in that: the system comprises a CWSN subsystem connected with a meteorological wireless sensor network and a CPC subsystem connected with a meteorological data observation center, wherein the CWSN subsystem and the CPC subsystem are communicated through an ADHOC network;

the CPC subsystem comprises a CPC network connection module, a network self-adaption module, a CPC automatic upgrading module and an instruction processing module,

wherein,

the CPC network connection module is connected with the CWSN subsystem through an ADHOC network, is connected with the meteorological data observation center through the Internet, receives data sent by the CWSN subsystem, forwards the data to the server side, receives data sent by the server and sends the data to the CWSN subsystem;

the network self-adaptive module is started when the CPC subsystem is connected with the internet for the first time, and the mode of accessing the network is adjusted according to the current connection state of the CPC subsystem and the network;

the instruction processing module is used for judging and processing an instruction sent by the meteorological data observation center;

the CPC automatic upgrading module acquires an executable file of a meteorological data observation center, which can be directly operated on an embedded platform, updates the existing operating program or adds an operating program which is not available on the embedded platform;

the CWSN subsystem comprises a serial port communication module, a CWSN network connection module, a WSN packet processing module, an XML file processing module and a CWSN automatic upgrading module:

wherein,

the serial port communication module is used for receiving data sent by the wireless sensor network, transmitting the data to the WSN packet processing module for processing, receiving an instruction from the CPC subsystem and transmitting the instruction to the wireless sensor network;

the WSN packet processing module is used for analyzing the WSN data packet received from the serial port communication module, transmitting the analyzed data to the XML file processing module, packaging the data transmitted from the XML file processing module into the WSN data packet and transmitting the WSN data packet to the serial port communication module;

the XML file processing module is used for analyzing the XML file sent from the CPC subsystem, transmitting the XML file to the WSN packet processing module, generating the XML file from the data transmitted from the WSN packet processing module, and sending the XML file to the CWSN network connection module;

the CWSN network connection module is used for connecting the CPC subsystem and carrying out data communication with the CPC subsystem;

the CWSN automatic upgrading module acquires an executable file of the meteorological data observation center, which can be directly operated on the embedded platform, through the CPC subsystem, and updates the existing operating program or adds an operating program which is not available on the embedded platform.

2. The middleware for a wireless sensor network based meteorological data observation system according to claim 1, wherein: and the network self-adaptive module automatically selects a smooth network for connection according to the sequence of the Ethernet, the wireless local area network and the 3G network.